praktikum i revisi2(2)
TRANSCRIPT
PRAKTIKUM I
KINETIKA ENZIM
Pengaruh pH Terhadap Aktivitas Enzim
Reagen :
Larutan Enzym (pankreatin atau amilase?) 1‰ (w/v)→ 1 gram enzim
Aquadest ad 1000 ml
Ambil labu ukur 1 L, timbang enzim 1 g masukkan labu ukur, lalu tambah
aquadest sampai 500 ml, campur (mix), tambah aquadest sampai dekat garis,
mix, lalu tetesi dengan aqadest sampai garis 1 L
NaCl 0.9 % (w/v) → 0,9 gram NaCl, aquadest ad 100 ml
Larutan Substrat (amylum 1%) → 1 gram amilum, aquadest ad 100 ml
(bukan 125 ml)
Penyangga pH: 4; 5; 6.5; 8; 103333
KI - KIO3 :
1. KI 5 gram
2. KIO3 0.375 gram aquadest netral ad 1 liter
3. NaOH 1 M → 2 ml
HCl 0.05 M → 4,15 ml add 1 liter aquadest (HCL 37%)
HgCl 2% (w/v) → 2 gram HgCl2, aqua ad 100 ml
Pembuatan;
1. pH 4 & pH 5
Acetate Buffer (sodium acetate-acetic acid buffer) pH 4-5.6
Sodium acetate 0.2M = 27.2 gm/1
CH3COONa.3H2O (MW - 136.09)
Acetic acid 0.2M
CH3COOH (MW = 60)
Add sodium acetate to acetic acid to give desired pH. Dilute with ddH20 (aquabidestilata = double distilled water) to desired molarity
Di Lab biokimia
Na Acetat 0.2 M → 0.2 x BM CH3COONa ( 82.04) = 16,408 gram,
aquadest ad 1L
32,816 g / 2liter
Kalau BM 136,09 (CH3COONa.3H2O ) maka Na asetat 27,2 g
Asam Asetat 0,2 M → BM = 60,05 ; 1 liter = 1,05 kg
= 60 x 0,2 x 1000 = 11,438 ml
1050 g
pH 4 = 17 ml Na Asetat + 83 ml As.Asetat 0,2 M atau
= 170 bag Na Asetat + 830 bag As.Asetat → 1 liter
Aturlah dengan penambahan sedikit asam asetat atau Na asetat kalau
pH kurang pas
pH 5 = 68 ml Na asetat + 32 ml asam asetat 0,2 M
atau di lab biokimia 7 bag Na Asetat + 3 bag As.Asetat
= 700 bag Na Asetat + 300 bag As.Asetat → 1 liter
2. pH 8 & 10
Borate Buffer pH 7.4-9.2
Borax (sodium tetraborate) 0.2M = 76.2 gm/ml
Na2B407.120H20 (MW = 381.37)
Boric acid 0.2M = 12.37 gm/1
H3BO>3 (MW = 61.83)
Add boric acid to borax solution until desired pH is reached.
Dilute to desired molarity with ddH20
Di Lab. Biokimia agak beda Hitungan?
Reagen A : 12,4048 g as.borat (boric acid) + 14,912 g KCl → 1 liter
Reagen B : NaOH 0,2 N → 8,002 g, aquadest ad 1 liter
pH 8 = 500ml A + 3,97 ml B, aqua ad 200 ml
= 250 A + 19,85 B → 1 liter
pH 10 = 50 ml A+ 43,9 ml B add aqua 200 ml
= 250 A + 219 ml B → 1 liter
3. pH 6,8
Plummer:
Buffer Na fosfat: x ml 0,2 M NaOH dimasukkan ke 50 ml 0,2 M Na H2PO4
Buffer K fosfat: x ml 0,2 M KOH dimasukkan ke 50 ml 0,2 M KH2PO4
x ml 3,5 5,8 9,1 13 18 24 30 35 40
pH 5,8 6,0 6,2 6,4 6,6 6,8 7,0 7,2 7,4
x ml 43 45 47
pH 7,6 7,8 8,0
Lalu encerkan (tambah aquadest) sampai garis 100 ml buffer 0,2M
Di Lab. Biokimia: Buffer 0,1M
Reagen A berisi KH2PO4 0,2 M → 27,232 g, aqua ad 1 liter (Lihat dulu BM
KH2PO4 pada botol)
NaOH 0,2 M
pH 6,8 = 50 ml A + 23,65 ml NaOH , aqua ad 200 ml (berarti buffer 0,1M)
= 250 ml A + 118,25 ml NaOH , aquadest add 1 liter
Atau pH 6,5 = 6 gr KH2PO4 + 2 gr Na2HPO4 → 1 liter (Hitungan?)
cat:atan:
- Siapkan 30 buah rak@5 tabung, 1 vol pipet 1 ml , erlenmeyer
- Cek pH tiap penyangga
- Siapkan buret @ reagen + beaker glass
- Siapkan cuvet & nyalakan spektrofotometnya
- Tiap akan praktek, lakukan percobaan terlebih dahulu sehari sebelumnya
Standardization buffers
pH=7.00 :Add 29.1 ml of 0.1 molar NaOH to 50 ml 0.1 molar potassium dihydrogen phosphate.
Alternatively :Dissolve 1.20g of sodium dihydrogen phosphate and 0.885g of disidium hydrogen phosphate in 1 liter volume distilled water.
Make up the following solutions(1) 0.1M disodium hydrogen phosphate (14.2g / l)
(2) 0.1M HCl(3) 0.1M NaOH
Mix in the following proportions to get the required ph
ph vol. of phosphate vol. of 0.1M HCl vol. of 0.1M NaOH
7 756.0 mls 244 mls
8 955.1 mls 44.9 mls
9 955.0 mls 45.0 mls
10 966.4 mls 33.6
11 965.3 mls 34.7
Working buffer: 0.1M 100 ml
Mix X ml of 0.2M dibasic sodium phosphate with Y ml monobasic sodium phosphate. Dilute to 100 ml with ddH20
pH (25 C) X ml Y ml
5.8 4.0 46.0
6.0 6.15 43.75
6.2 9.25 40.75
6.4 13.25 36.75
6.6 18.75 31.25
6.8 24.5 25.5
7.0 30.5 19.5
7.2 36.0 14.0
7.4 40.5 9.5
7.6 43.5 6.5
7.8 45.75 4.25
8.0 47.35 2.65
PRAKTIKUM II
PENGARUH SUHU PADA RX. ENZIMATIK
- Reagen yang digunakan sama seperti Praktikum I, tapi hanya menggunakan
buffer pH 6,5
- Siapkan es batu, penangas air
PRAKTIKUM III
PENGARUH AKTIVATOR, INHIBITOR, DAN KADAR ENZIM
- Reagen yang digunakan sama seperti Praktikum I
- HgCl2 1%
- Mengggunakan buffer pH 6,5
PRAKTIKUM IV
BEBERAPA CONTOH ENZIM
A. UREASE
Ureum 1 % (w/v) (buat 3x) → usahakan baru
PP 1 %
- 1 gr PP, alkohol 95% ad 100 ml
PP 2% (w/v)
Urease
- Bila pakai kedelai, 2% dilarutkan dalam NaCl 0,9 %
HgCl2 2%
B. SUKSINAT DEHIDROGENASE (KATAK)
Larutan penyangga phospat pH 6,8
Natrium Suksinat 0,05 N
Cara buat: 1 gral = 2 grek ( 1 mmol = 1 meq)
BM = 198,13
0,05 x BM = 4,95325 gr, aquadest ad 1 liter
2
Methylene Blue ( 1: 20.000) = w/v → 0.05 gr / 1000 ml
PARAFIN
Daging ayam dicincang dimasukkan 3 tabung, @ ± 1 gram
C. Enzim Schardinger → bahan susu (baru)
Reagen Methylene Blue Formaldehide
25 mg methylene blue dilarutkan dlm 195 ml air dan 5 ml formaldehid 40%
PARAFIN
D. PEROXIDASE SUSU
BENZIDIN 4% (w/v) DAN 1 ml H2O2 3%
4,33 ml as.cuka glasial dimasukkan erlenmeyer + ( 0,5 gr Benzidin
(dibuat baru) + aquadest kira-kira 20ml) + dipanasi 50o C
→ apabila diencerkan sehingga volume 100 ml (pindah ke labu ukur
100 ml, bilas erlenmeyer dengan aquadest , masukkan labu ukur
tersebut, sampai volume larutan 100 ml, berarti kadarnya menjadi 4%
H2O2 3% (w/w)
Lihat botol kadar berapa? (w/w = 30%?) , lalu encerkan (10X?)
Cat:
- Siapkan 3 penangas air → 37o C, 2 mendidih
- Kertas saring
- BENZIDIN 4% DAN H2O2 3% → simpan dalam refrigerator
- Susu harus baru
PRAKTIKUM VII
CAIRAN EMPEDU, EMPEDU, VITAMIN & INDOL --belum
R. Pettenkofer
- H2SO4 pekat
- empedu encer (10x) [2 ml] cincin ungu
- sukrosa 10% (baru) [ 1 tts]
R. Hay
- Aquadest
- Empedu encer mengendap
- Bubuk belerang
R. Gmellin
- Empedu pekat
- HNO3 pekat
R. Joles
- Urina [5 ml]
- Thymol 5% dlm alkohol [ 15 tts]
- FeCl3 0,3 % dlm HCl 37% [5 ml ]
- Chloroform [ 1 ml ]
1. Vitamin A (tabung harus kering)
- Minyak ikan [ 1 tts ] kulkas
- Chloroform kering [ 5-6 tts ] → chloroform + Na sulfatanhidrid
- As. Cuka anhydrida [ 1-2 tts ]
- Antimonium Trichlorida (SbCl3) dlm chloroform kering yg baru & jenuh
[ 20 tts ]
2. Vitamin B
- B1 [ 1ml ]
- Alkohol 80 % [ 1 ml ]
- NaOH 40% [ 0,6 ml ]
- Lar. K3Fe(CN)6) [ 3 tts ]
- Alkohol pekat [ 5 ml ]
Bolak balik beberapa kali spy homogen, lihat hasilnya di bawa UV (biru)
3. Vit B2
- Alkohol 80% [ 5 ml ]
- Susu sapi [ 2 ml ]
Homogenkan lalu dilihat di bawah sinar UV (hijau)
4. Vit C (titrasi dg Dip)
- TCA 10%
- DIP (suasana basa→ biru, asam→ merah muda)
Pembuatan Dip;
- 130 mg 2,6 DIP + 500 ml air mendidih lalu setelah dingin + 150 mg
NaHCO3, simpan dalam gelap
- Digunakan vit. C 50 mg dalam 1 liter aquadest
- Lakukan titrasi, 5 ml vit C + 2 ml TCA 10 % lalu titrasi dengan DIP
- Perhitungan :
5 x 50 mg = 0.25mg ~ a titrasi
1000
1 ml DIP ~ 0.25
A titrasi
Ket:
- untuk B1& B2 2 ml susu + 5 ml alkohol 80% → kocok→ sentrifuge→
saring bagi 2
- B1 → suspensi + 0.6 ml NaOH 40 % + 3 tetes K3Fe (CN)6 2%
- B2 → suspensi dilihat di sinar UV
- Siapkan sinar UV
- Sentrifuge
- Tutup tabung
PRAKTIKUM VI
PENCERNAAN MAKANAN (SALIVA)
PP 1 ‰ → pelarut alkohol 95%
Litmus 2 ‰ → pelarut aquadest
Merah Congo → 0,5 gr merah congo dlm 90 ml air + 10 ml alkohol 95%
CCl4
NaOH 10%
CuSO4 1%
As. Cuka (as. Asetat) 5%
HNO3 5%
AgNO3 1%
HCl 2% & 5%
BaCl2 2%
HgCl2 2%
H2SO4 5%
KI 2%
Amylum 1% dibuat baru
FeCl3 2%
HNO3 pekat
Am. Molibdate 2%
Am. Oxalat jenuh
Lugol
- 5 gr iodium/ iodine/iodida ( I2 ) aquadest 100 ml
- 10 gr KI
Fehling A
- 34,65 gr CuSo4 dlm 500ml aquadest
Fehling B
- 125 gr KOH + KNa Tartrat ad 500 ml aquadest
Cat:
- Siapkan 30 buah rak@17 tabung, erlenmeyer, corong, kapas gulung, kasa
- Meletakkan reagen2 pada meja + @1 pipet pasteur
- Amilum & aquadest dituang di buret
- Memanaskan air untuk px. phospat
PRAKTIKUM V
MAKANAN ( AIR SUSU SAPI)
MM / MR 2% → baru
- 2% dalam alkohol 50%
PP 1%
MP / phenol red 1 %
Chloroform
NaOH 10% → 300 ml
As. Cuka 6% → 500 ml
Aceton ( panaskan dalam air mendidih)
Fehling A & B
Biuret
I. 3 gr CuSO4 5H2O (dilarutkan dulu dlm 500ml aquadest)
II. 9 gr KNa Tartrat 4H2O
III. 24 gr NaOH (dilarutkan dulu dlm 100 ml aquadest)
IV. 5 gr KI → ditambahkan terakhir supaya tidak tereduksi → add 1 l
R.Millon
- Hg : HNO3 pekat = 1 : 2
- HNO3 = 150 ml
Hg = 70 gram
Hopkins Cole → buat 200 ml
- 40 gr Mg powder (Na amalgam) + as. Oxalat jenuh → dibiarkan
semua gas keluar → disaring → diencerkan 2-3x ( dilakukan di kamar
asam & bawahx dikasih es)
HNO3 pekat
NaOH 40%
Am. Molibdate 2%
Cat:
- Siapkan cawan porselin
- Pengukur berat jenis
- Kertas saring
- Corong
- Penangas air
- Xantoprotein → HNO3 pekat + NaOH 40%
- PO4 → Am. Molibdate + HNO3 pekat
- Pipet pasteur
PRAKTIKUM VIII
TITRASI FORMOL
NaOH 0,1 N ditritasi dg As. Oxalat 0,1 N dg PP
PP 1 ‰
Formalin ( pengenceran 3x)
Gelatin 4%
- Masukkan gelatin sedikit demi sedikit ke aquadest (air panas)
- Dibuat pH 8 dg menambah NaOH 40% tetes demi tetes
Pancreatin 4%
Cat:
- 30 kelompok buat gelatin 1 l → 42 gr, pancreatin 200 ml → 8 gram
- AAM 20 kelompok, gelatin 500 ml → 20 gr, pancreatin 150 ml → 6 gram
- Waterbath 37o C
PEMBEKUAN DARAH
K. oxalat 10%
Na. citrat jenuh
Na. fluorida 10%
CaCl2 2%
CaCl2 bubuk
Prosedur:
A. Pencegahan Pembekuan Darah
Pembekuan darah dapat dicegah dg mengikat ion C++ dg berbagai
reagen. Sediakan 4 tabung ( A, B, C, D ) dan masukkan:
- A. Larutan K. Oxalat 10% 2 tetes
- B. Larutan Na. Citrat jenuh 1 tetes
- C. Larutan Na. fluorida 10% 2 tetes
- D. Tidak diberi apa2
Putar2 tabung A,B,C supaya dindingnya basah + @ tabung 5 tetes darah
→ Homogenkan → diamkan 5 menit → amati ada bekuan/tidak.
Untuk membuktikan bahwa pembekuan dicegah karena ion C++ terikat,
maka + CaCl2 bubuk pada tabung yang tidak menunjukkan pembekuan
→
terjadi pembekuan
B. Pembekuan Darah
Dalam 3 tabung reaksi A, B, C + @ 1 ml darah oxalat, lalu:
- Tabung A + 2 tetes serum
- Tabung B + 2 tetes lar. CaCl2 2%
- Tabung C tidak diberi apa-apa
Inkubasi 3 tabung pada 37oC, 10 menit → goyang untuk mengetahui
pada tabung mana terjadi pembekuan. Hanya pada tabung Ctidak terjadi
pembekuan.
Tabung A terjadi pembekuan karena serum mengandung trhombin yang
dapat merubah fibrinogen menjadi fibrin tanpa memerlukan C++
Tabung B terjadi bekuan darah karena adanya ion2 Ca yang
memungkinkan terbentuknya trombin dari protrombin oleh trombokinase.
GLUKOSA DARAH
Stock glucose standard 1000mg
- 10 gram dextrose a.p. anhydour, larutkan dalambenzene acid pekat,
add 1 liter
TCA 5%
- 5 ml TCA dalam 100 ml aquadest
Orto toluidin 8,6 % → buat baru
- 8,6 ml Orto toluidin + add 100ml asam aetic glasial
- Simpan dalam botol coklat dalam refrigerator
Procedure:
Sample Standard Blanko
TCA 2,0 ml 2,0 ml -
Whole blood 0,2 ml - -
Standarg glucose - 0,2ml -
Lalu centrifuge
Filtrat 1,0 ml - -
Standard - 1,0 ml -
TCA - - 1,0 ml
O. toluidin 4 ml 4 ml 4 ml
Campur, lalu dipanaskan 80o C pada waterbath, dinginkan. Lalu baca pada
spektrofotometer λ = 625 nm
Lain-lain:
Cara pembuatan reagen lihat Hawk (buku lama) atau lihat di internet percobaan apa,
cara nya dan cara pembuatan reagennya. Janga lupa cek botolnya baik isi maupun
kadarnya , rumus dan lainlain
Dari internet
Acetic acid 1 N =6% ,
BM = 60,028 g
Sediaan ada yang:
Acetic acid glacial = 17,4 N = 99,7%
kalau buat 6% caranya V1X N1 = V2 XN2
6X 99,7 ml = 99,7 X 6 ml
Jadi ambil 6 ml acetic acid glasial, aqua ad 99,7 ml
(pengenceran = 99,7/6X) atau 16,6X
Kalau 1N berarti 1ml glasial acetic acid, aquadest ad 17,4 ml
Atau 1/17,4 X 99,7 % = 5,07%
Acetic acid 36% (w/w)
Di botol dari pabrik?
Acetic acid 99,8% 2,268 kg? berarti =2263,464 : 60,054 = 37,690 mol
Volume botol tersebut 2 L? (cek dulu) 37,690: 2 = 18,85M
1M atau 1 N acetic acid = 99,7% X1/18,85 = 5,305%
1. [PDF]
Microsoft Word - Practical Buffer Prep
90k - Adobe PDF - View as htmlacid and acetate. And lastly, what does the sodium have to do with the buffer? Well, ... hydroxide and hydrochloric acid. Your object will be to prepare at ...www.tamucc.edu/~plarkin/4101folder/CHEM 4401 L3 Buffer Prep.pdf
2. PASCO : Chemistry : Quantities and Reactions : Buffers
... (hydrochloric acid) and of a strong base (sodium hydroxide) on ... 0.1 M acetic acid (CH3CO2H) 1.0 M hydrochloric acid (HCl) 0.1 M sodium acetate (CH3CO2Na) ...www.pasco.com/chemistry/quantities-and-reactions/buffers.cfm - Cached
3. "A" Standard Solutions: Suppliers of PH Buffers like Acetate Buffer ...
... (Contains: Sodium Acetate, Sodium Chloride, Hydrochloric Acid and Acetone) ... Contains: Sodium Hydroxide and Potassium Iodide (Contains No Azide's) A-162 ...www.redbirdservice.com/catalog23/solutions A.htm - 68k - Cached
4. EXP 18E: Acid /Base Buffers
... of adding sodium acetate to an acetic acid solution, the most ... buffer solution by adding an excess amount of acetic acid to a sodium hydroxide solution. ...pages.towson.edu/debye/chem111/F2000/111exp18acidbase_e.html - Cached
5. EXP 22C,E: Salt Hydrolysis and Buffer Solutions
Instead of adding sodium acetate to an acetic acid solution (the most direct way ... acid and sodium hydroxide solutions used in making the buffer; compare this ...pages.towson.edu/debye/chem111/experiments/111_exp18CEsaltbuffer.html - Cached
6. [PPT]
Activity Coefficient..>
475k - Microsoft Powerpoint - View as html... (sodium hydroxide) 0.10M HCl (hydrochloric acid) ... a = 0.025M acetic acid. s = 0.025M sodium acetate. Buffer pH Titrations. 1. Calibrate pH meter ...iris.nyit.edu/~source/Activity Coefficients and Buffer Capacity Tit...
7. CHEM 215 L Preparation of a Buffer
a. Make a pH = 3.00 buffer using citric acid and sodium hydroxide. b. Make a pH = 5.00 buffer using sodium acetate and hydrochloric acid. ...campbell.edu/faculty/bryan/CHEM215/Lab_Handouts/Buffer_Preparation.htm - Cached
CHEM 215 L Preparation of a Buffer (Revised 11/2004)
Supplemental Reading:
Read Chapter 10 and 11 in Quantitative Analysis by Harris (6<sup>th edition) for more details on
buffer preparation.
See Appendix G, Harris for various K<sub>a Values.
Manual for pH meter : http://www.denverinstrumentusa.com/media/pdf/op-man-basic-ph-rev-g.pdf (see link on CHEM 215 Webpage)
Introduction:
Buffers are solutions which contain reasonable amounts of a weak conjugate acid -base
pair. A buffer solution has the ability to resist large changes in pH, because when
H<sub>3</sub>O+ (aq) or OH- (aq) is added to the solution is converted to the conjugate
form of the weak conjugate acid-base pairs by one of the following equations:
H<sub>3</sub>O+ (aq) + A- (aq) D HA (aq) + H<sub>2</sub>O (l)
OH- (aq) + HA (aq) D</span><b><span style="font-size: 11pt;">A- (aq) +
H<sub>2</sub>O (l)
The pH of a buffer can be calculated by the Henderson-Hasselbalch equation:
pH = pKa + log
where
n<sub>B = moles (or mmoles) of the conjugate base
n<sub>A = moles (or mmoles) of the conjugate acid
pKa = -log (Ka) for the Ka of the conjugate acid
The buffer may be prepared (direct method) by mixing the appropriate moles of
conjugate acid (n<sub>A) with the appropriate number of moles of conjugate base
(n<sub>B). If the conjugate acid and base are not both available, then the buffer may be
prepared (indirect method) by partial conversion of the conjugate acid to the conjugate
base (or vice versa) using a strong acid or base as appropriate. Note: Dilution of the
buffer will cause slight changes in pH because of changes in ionic strength. The buffer
capacity depends on the actual moles of conjugate acid and base that are present.
Objective:
Students will calculate and prepare buffers at a specific pH�s. Students will apply theoretical knowledge of the Henderson-Hasselbalch equation and activity coefficients to buffer preparation and to pH calculations.
Experimental:
(Prepare any three of the following.) Show your calculations to the instructor before
proceding. Calculate the number of grams of solid and mL of 1.0 M NaOH or 1.0 M HCl
needed to prepare your buffer.
a. Make a pH = 3.00 buffer using citric acid and sodium hydroxide.
b. Make a pH = 5.00 buffer using sodium acetate and hydrochloric acid.
c. Make a pH = 6.50 buffer using sodium citrate and hydrochloric acid.
d. Make a pH = 9.00 buffer using ammonium chloride and sodium hydroxide.
1. Prepare each buffer to be 0.050 M in the conjugate acid, and 100 mL total
volume. (Dilute to volume with deionized water.) If both of your reagents are available
as a solid, you should calculate the mass of each reagent you are going to mix. If only
one reagent is available as a solid, you will have to add 1.00 M NaOH or HCl to create its
conjugate form in solution. Show your calculation of the mass of reagent(s) and, if
necessary, the volume of strong acid or base you will mix to create your buffer. Show
your calculations to the lab instructor before you proceed.
2. Calibrate your pH meter then measure the pH of your solution with a the pH
meter, and record the pH in your notebook. How close did you come to your target pH?
Can you think of some reasons why the actual pH of your buffer may differ from the
theoretical pH?
3. Challenge- Calculate the ionic strength of your solution. See if you can
estimate the �true� pH of your solution using Equation 10-18 (page 190) of the Harris
Text.
4. The final step in buffer preparation is to bring the solution to the desired pH by
the addition of strong acid or base. Transfer your buffer to a 250 mL beaker and add
enough 1.0 M NaOH or HCl from a buret, with magnetic stirring, to bring the pH to the
target. The new volume of your buffer is the original 100 mL plus the volume of acid or
base you just added. Calculate the new theoretical pH by calculating the new weak base
to conjugate acid ratio and using the Henderson-Hasselbalch equation. To get the new
ratio, you will need to calculate the moles of strong acid or base you have just added.
Compare the new actual and theoretical pH.
Available Reagents:
1.0 M NaOH (aq), 1.0 M HCl (aq),
Citric Acid Monohydrate (H<sub>3</sub>Cit � H<sub>2</sub>O) , 210.14 g/mole
Sodium Acetate Trihydrate (NaC<sub>2</sub>H<sub>3</sub>O<sub>2 �
3H<sub>2</sub>O), 136.08 g/mole
Sodium Citrate Dihydrate (Na<sub>3</sub>Cit � 2H<sub>2</sub>O), 294.10 g/mole
Ammonium Chloride (NH<sub>4</sub>Cl), 53.49 g/mole
See your textbook for various pKa�s. (Appendix G)
Formulations of Commonly Used Buffers and Media:
These are the formulations of buffers we have successfully used over the years. If they are not the same as other formulations the differences are probably not significant.
Citric Saline: To make 500ml of 10X solution 50g KCl 22g Sodium CitrateDissolve in distilled water and bring to 500ml. Sterilize by autoclaving.
Dilute to 1X with sterile distilled water and use to remove adherent cells from tissue culture dishes. To do this aspirate off culture media and replace with 1X solution. Let cells sit in the incubator at 37°C, and then monitor cells with microscope, generally they are no longer adherent after as little as 5 minutes. Collect cells by centrifugation, replace citrate saline with regular culture media and replate cells. Cheap and Efficient!
Mounting Media for Immunofluorescence Microscopy:To make 50mls of add 40g glycerol to 5mls of 10X PBS and make up to 50mls volume. To stain for DNA add Hoechst 33258 dye to a final concentration of 2.5mM. But if you put the Hoechst dye into your media, be very careful, since this dye is a DNA intercalating agent which may well be carcinogenic.
Phosphate Buffered Saline: To make 1L of 10X solution 2g KH<sub>2</sub>PO<sub>4 Potassium dihydrogen phosphate, a.k.a. potassium phosphate monobasic 14.1g Na<sub>2</sub>HPO<sub>4 Anhydrous sodium phosphate, a.k.a. sodium phosphate dibasic. 2g KCl Potassium Chloride 80g NaCl Sodium ChloridepH to 7.4 with 5N NaOH. (be careful, concentrated NaOH, perhaps surprisingly given that every lab has some around, is quite dangerous. It can blind you if it gets in your eyes!)
1X PBS is 1.47mM KH<sub>2</sub>PO<sub>4, 10mM Na<sub>2</sub>HPO<sub>4, 2.7mM KCl, 137mM NaCl pH=7.4. It is a more or less physiological buffer which living mammalian cells can tolerate at least for a short time. It is frequently used to wash cells prior to protein extraction or immunostaining. It is also useful for antibody incubations in immunocytochemical staining of cells in tissue culture and sections. One caveat is that phosphatase based detection systems are inhibited by high concentrations of phosphate, the phosphatase reaction product, so you need to do a wash in some sort of
phosphate free buffer before you use these. For antibody staining and washing you can also add 0.1% Tween 20 (Polyoxyethylene 20-sorbitol monolaurate) or 0.1% Triton X-100 non-ionic detergents to reduce background staining.
Tris Buffered EDTA (TBE):To make 1L of 10X solution107.8g Tris base~55g Boric acid7.44g EDTAadd less than total amount of Boric acid, dissolve this and the Tris in 800 ml of distilled water and make pH to 8.3 by adding more boric acid. Finally make to 1L final volume.This is the standard buffer for running DNA in agarose gels.
Tris Buffered Saline: To make 1L of 10X solution 12.1g Tris base 87.66g NaClpH with concentrated HCl (be careful!) to 7.5
1X TBS is 10 mM Tris/HCl, 150 mM NaCl, pH=7.5. We use TBS routinely for ELISA, immunoblots etc. Can also add 0.1% Tween 20 or 0.1% Triton X-100 non-ionic detergents to final concentration of 0.1% reduce background.
©EnCor Biotechnology Inc. 2007-2008. To go to the EnCor homepage press www.encorbio.com.
Phosphate buffered saline
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Phosphate buffered saline (abbreviated PBS) is a buffer solution commonly used in biological research. It is a salty solution containing sodium chloride, sodium phosphate , and (in some formulations) potassium chloride and potassium phosphate. The buffer helps to maintain a constant pH. The osmolarity and ion concentrations of the solution usually match those of the human body (isotonic).
Contents 1 Applications 2 Preparation 3 References
4 External links
[edit] Applications
PBS has many uses because it is isotonic and non-toxic to cells. It can be used to dilute substances. It is used to rinse containers containing cells. PBS can be used as a diluent in methods to dry biomolecules, as water molecules within it will be structured around the substance (protein, for example) to be 'dried' and immobilized to a solid surface[citation needed]. The thin film of water that binds to the substance prevents denaturation or other conformational changes. Carbonate buffers may be used for the same purpose but with less effectiveness[citation needed]. PBS can be used to take a reference spectrum when measuring the protein adsorption in ellipsometry[citation needed].
Additives can be used to add function. For example, PBS with EDTA is also used to disengage attached and clumped cells. Divalent metals such as zinc, however, cannot be added as this will result in precipitation. For these types of applications, Good's buffers are recommended.
[edit] Preparation
There are many different ways to prepare PBS. Some formulations do not contain potassium, while others contain calcium or magnesium[1]. One of the most common preparations is described below.
The simplest way to prepare a PBS solution is to use PBS buffer tablets. They are formulated to give a ready to use PBS solution upon dissolution in a specified quantity of distilled water. They are available in the standard volumes: 100, 200, 500 and 1000 ml [2].
A 10 liter stock of 10x PBS can be prepared by dissolving 800 g NaCl, 20 g KCl, 144 g Na<sub>2</sub>HPO<sub>4 and 24 g KH<sub>2</sub>PO<sub>4 in 8 L of distilled water, and topping up to 10 L. The pH is ~6.8, but when diluted to 1x PBS it should change to 7.4. When making buffer solutions, it is good practice to always measure the pH directly using a pH meter. If necessary, pH can be adjusted using hydrochloric acid or sodium hydroxide. On dilution, the resultant 1x PBS should have a final concentration of 137 mM NaCl, 2.7 mM KCl, 10 mM Sodium Phosphate dibasic, 2 mM Potassium Phosphate monobasic and a pH of 7.4.
Another preparation is described in Molecular Cloning by Sambrook, Fritsch and Maniatis, Apendix B.12[3] as follows:
For 1 litre of 1x Phosphate-buffered saline (1x PBS buffer) use:..
- Dissolve in 800 ml of distilled H<sub>2</sub>O:- 8 g of NaCl- 0.2 g of KCl- 1.44 g of Na<sub>2</sub>HPO<sub>4- 0.24 g of KH<sub>2</sub>PO<sub>4- Adjust the pH to 7.4 with HCl or NaOH- Add H<sub>2</sub>O to 1 liter.
Dispense the solution into aliquots and sterilize them by autoclaving (20 min, 121°C, liquid cycle). Store at room temperature.
[edit] References
1. ̂ Dulbecco, R. et al. (1954): Plaque formation and isolation of pure lines with poliomyelitis viruses. In: J. Exp. Med. vol. 99 (2), pp. 167-182. PMID 13130792
2. ̂ Medicago AB, (2003) Phosphate buffered saline pH 7.4 specification sheet
3. ̂ Sambrook, Fritsch, and Maniatis (1989) Molecular Cloning: A Laboratory Manual, 2nd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, volume 3, appendix B.12
2.2.1 Definition of a Buffer
A buffer is a solution containing substances which have the ability to minimise changes in pH when an acid or base is added to it 1.
A buffer typically consists of a solution which contains a weak acid HA mixed with the salt of that acid & a strong base eg NaA. The principle is that the salt provides a reservoir of A- to replenish [A-] when A- is removed by reaction with H+.
The Major Body Buffer Systems
Site Buffer System Comment
ISF Bicarbonate For metabolic acids
Phosphate Not important because concentration too low
Protein Not important because concentration too low
Blood Bicarbonate Important for metabolic acids
Haemoglobin Important for carbon dioxide
Plasma protein Minor buffer
Phosphate Concentration too low
ICF Proteins Important buffer
Phosphates Important buffer
Urine Phosphate Responsible for most of 'Titratable Acidity'
Ammonia Important - formation of NH<sub>4+
Bone Ca carbonate In prolonged metabolic acidosis
BUFFERS
The quality of fixation is influenced by pH and the type of ions present.
The choice of buffer is based on:
1. the buffering capacity in the desired pH range with the ability to maintain constant pH during fixation.
2. the side effects which vary with the tissue type:
a. suitable osmolarity so that cells and organelles neither swell nor shrink during fixation.
b. suitable ionic concentration so that materials are neither extracted nor precipitated during fixation.
c. the toxicity of the buffer.
Criteria of a good buffer :
1. pKa: usually between 6 and 8 desired for biological specimens.
2. Maximum solubility in water and minimum solubility in all other solvents.
3. Reduced ion effects.
4. Dissociation of buffer least influenced by buffer concentration, temperature and ionic composition.
5. Resistance to oxidation (stable).
6. Inexpensive and easy to prepare.
7. No reaction with fixation.
Common Buffers
I. Phosphate Buffer (Sorenson's buffer) pH 5.8-8
Advantages:
1. Most physiological of common buffers. Mimics certain components of extracellular fluids.
2. Non-toxic to cells.
3. pH changes little with temperature.
4. Stable for several weeks at 4 C.
Disadvantages:
1. Precipitates more likely to occur during fixation. Tends to form precipitates in presence of calcium ions. Precipitates uranyl acetate and tends to react with lead salts.
2. Becomes slowly contaminated with micro-organisms
Preparation of Buffer
Stock solutions:
0.2M dibasic sodium phosphate 1 liter
Na<sub>2</sub>HPO<sub>4*2H<sub>2</sub>0 (MW = 178.05) 35.61 gm
or
Na<sub>2</sub>HPO<sub>4*7H<sub>2</sub>0 (MW = 268.07) 53.65 gm
or
Na<sub>2</sub>HPO<sub>4*12H<sub>2</sub>0 (MW = 358.14) 71.64 gm
+ ddH<sub>2</sub>0 to make 1 liter
0.2M monobasic sodium phosphate 1 litter
NaH<sub>2</sub>PO<sub>4*H<sub>2</sub>0 (MW = 138.01) 27.6 gm
or
NaH<sub>2</sub>PO<sub>4*2H<sub>2</sub>0 (MW = 156.03) 31.21 gm
+ ddH<sub>2</sub>0 to make 1 liter
Working buffer: 0.1M 100 ml
Mix X ml of 0.2M dibasic sodium phosphate with Y ml monobasic sodium phosphate. Dilute to 100 ml with ddH<sub>2</sub>0 or dilute 1:1 with fixative.
pH (25 C) X ml Y ml
5.8 4.0 46.0
6.0 6.15 43.75
6.2 9.25 40.75
6.4 13.25 36.75
6.6 18.75 31.25
6.8 24.5 25.5
7.0 30.5 19.5
7.2 36.0 14.0
7.4 40.5 9.5
7.6 43.5 6.5
7.8 45.75 4.25
8.0 47.35 2.65
Osmolarity is adjusted by varying the molarity of phosphates or by the addition of sucrose, glucose or sodium chloride.
At pH 7.2:
0.10M = 226 mOs (milliosmoles)
0.05M = 118 mOs
0.075 = 180 mOs
0.15M = 350 mOs
II. Cacodylate Buffer (arsenate buffer) pH 5-7.4
Advantages:
1. Easy to prepare.
2. Stable during storage for long periods of time.
3. Does not support growth of microorganisms.
4. Precipitates usually do not occur. Precipitates do not occur at low concentrations of calcium.
Disadvantages:
1. Toxic. Contains arsenic.
2. Unpleasant smell.
Preparation of Buffer :
Stock solutions:
0.2M sodium cacodylate 1 liter
Na(CH<sub>3)2</sub>As0<sub>2*3H<sub>2</sub>0 (MW = 195.92) 42.8 gm
+ ddH<sub>2</sub>0 to make 1 liter
0.2M HC1
Conc. HC1 (36-38%) 10 ml
ddH<sub>2</sub>0 603 ml
Working buffer : 0.1M 100 ml
Adjust 50 ml of 0.2M sodium cacodylate to desired pH with 0.2M HC1. Dilute to 100 ml with ddH<sub>2</sub>0 or dilute 1:1 with fixative.
pH 0.2M HC1 (ml)
6.4 18.3
6.6 13.3
6.8 9.3
7.0 6.3
7.2 4.2
7.4 2.7
Buffer may also be made with cacodylic acid.
Stock solutions:
0.2M cacodylic acid 1 liter
(CH<sub>3)2</sub>AsO<sub>2</sub>H (MW = 138.0) 27.6 gm
+ ddH<sub>2</sub>0 to make 1 liter
0.2M NaOH 100 ml
NaOH (MW = 40) 0.8 gm
+ ddH<sub>2</sub>0 to make 100 ml
Working buffer : 0.1M
Adjust 50 ml of 0.2M cacodylic acid to desired pH with 0.2M NaOH. Dilute to 100 ml with ddH<sub>2 or dilute 1:1 with fixative.
III. Veronal-acetate Buffer (Michaelis buffer)
Advantages:
Useful for block staining with uranyl acetate since precipitates do not form.
Disadvantages:
1. Reacts with aldehydes.
2. Poor buffer at physiological pH.
3. Supports growth of micro-organisms.
4. Contains barbiturate.
Preparation of Buffer :
Stock solution: 0.28M 100 ml
Sodium veronal (barbitone sodium)
C<sub>8</sub>H<sub>11</sub>0<sub>3</sub>N<sub>2</sub>Na (MW = 206.18) 2.89 gm
Sodium acetate (anhydrous)
CH<sub>3</sub>C00Na (MW = 82.03) 1.15 gm
or
Sodium acetate (hydrated)
CH<sub>3</sub>C00Na*3H<sub>2</sub>0 (MW = 136.09) 1.90 gm
+ ddH<sub>2</sub>H<sub>2</sub>0 to make 100 ml
Solution is stable and may be stored for some months at 4 C.
Working buffer :
Veronal acetate stock solution 5 ml
ddH<sub>2</sub>0 15 ml
Add 0.1 HC1 gradually to desired pH.
Solution cannot be stored.
Supports growth of bacteria and molds even at 4 C.
Crystallizes in absence of osmium tetroxide.
IV. Collidine Buffer pH 7.25-7.74
Advantages:
1. Maximum buffering capacity about 7.4.
2. Stable indefinitely at room temperature.
3. Useful for fixation of large tissue blocks. Aids penetration of fixative due to extractive effects (see disadvantage 1).
Disadvantages:
1. Not suitable as buffer during primary fixation with osmium tetroxide due to considerable extraction of tissue components.
2. Use leads to lysis of cytoplasmic matrix and extensive membrane destruction when used with paraformaldehyde fixatives.
3. Use gives poorer results with glutaraldehyde than those obtained with phosphate or cacodylate buffer.
Preparation of Buffer :
Stock solution: 0.4M 100 ml
Pure s-collidine 5.34 gm
2,4,6(CH<sub>3)3(C<sub>2</sub>H<sub>5</sub>N) (MW = 121.18)
+ ddH<sub>2</sub>0 to make 100 ml
Working buffer : 0.2M 100 ml
Adjust 50 ml of s-collidine stock solution to desired pH with 1N HC1. Dilute to 100 ml with ddH<sub>2</sub>0.
pH 1N HC1 (ml)
7.25 22
7.33 20
7.41 18
7.5 16
7.59 14
7.67 12
7.74 10
V. Tris buffer
Advantages:
1. Good buffering capacity at higher pH required for some tissues and some cytochemical procedures.
2. "More or less" physiologically inert.
Disadvantages:
1. pH changes with temperature. Must be measured at desired temperature.
2. pH must be measured with certain type of electrode.
Preparation of Buffer :
A. Tris Buffer pH 7.1-8.9
Stock solution 0.2M 1 liter
Tris(hydroxymethyl)aminomethane 24.2 gm
H<sub>2</sub>NC(CH<sub>2</sub>0H)3 (MW = 121.13)
+ ddH<sub>2</sub>0 to make 1 liter
Working buffer : 0.1M 100 ml
Adjust pH of 50 ml of stock solution with 0.1M NaOH. Dilute to 100 ml with ddH<sub>2</sub>0.
B. Tris-maleate Buffer pH 5.8-8.2
Stock solution: 0.2M liter
Tris(hydroxymethyl)aminomethane 24.2 gm
Maleic acid 23.2 gm
HO<sub>2</sub>CCH:CHCO<sub>2</sub>H (MW = 116.07)
+ ddH<sub>2</sub>0 to make 1 liter
or
Trizima-maleate (MW = 237.2) 47.4 gm
+ ddH<sub>2</sub>0 to make 1 liter
Working buffer : 0.2M 100 ml
Adjust 50 ml of stock solution to desired pH with 0.1M NaOH. Dilute to 100 ml with ddH<sub>2</sub>0.
VI. Special Buffers Used for Cytochemical Reactions .
A. Acetate Buffer (sodium acetate-acetic acid buffer) pH 4-5.6
Sodium acetate 0.2M = 27.2 gm/1
CH<sub>3</sub>CO<sub>2</sub>Na*3H<sub>2</sub>0 (MW - 136.09)
Acetic acid 0.2M
CH<sub>3</sub>COOH (MW = 60)
Add sodium acetate to acetic acid to give desired pH. Dilute with ddH<sub>2</sub>0 to desired molarity.
B. Borate Buffer pH 7.4-9.2
Borax (sodium tetraborate) 0.2M = 76.2 gm/ml
Na<sub>2</sub>B<sub>4</sub>0<sub>7*120H<sub>2</sub>0 (MW = 381.37)
Boric acid 0.2M = 12.37 gm/1
H<sub>3</sub>BO<sub>3 (MW = 61.83)
Add boric acid to borax solution until desired pH is reached. Dilute to desired molarity with ddH<sub>2</sub>0.
C. Citrate Buffer (sodium citrate-citric acid buffer) pH 3-6.2
Sodium citrate 0.2M = 58.8 gm/1
Na<sub>3</sub>C<sub>6</sub>H<sub>5</sub>0<sub>7*H<sub>2</sub>0 (MW = 294.12)
Citric acid 0.2M = 42.02 gm/1
C<sub>6</sub>H<sub>8</sub>0<sub>7*H<sub>2</sub>0 (MW = 210.14)
Mix citric acid and sodium citrate to give desired pH. Dilute with ddH<sub>2</sub>0 to desired molarity.
D. Dimethylglutarate Buffer pH 3.2-7.6
Dimethylglutaric acid 0.1M = 16.02 gm/1
C<sub>7</sub>H<sub>12</sub>0<sub>4 (MW = 160.2)
Add 0.2N NaOH to give desired pH. Dilute with ddH<sub>2</sub>0 to desired molarity.
E. Succinate Buffer pH 3.8-6
Succinic acid 0.2M = 23/62 g/1
C<sub>4</sub>H<sub>6</sub>0<sub>2 (MW = 118.09)
Add 0.2M NaOH to desired pH. Dilute with ddH<sub>2</sub>0 to desired molarity.
F. Maleate Buffer (sodium hydrogen maleate buffer) pH 5.2-6.8
Stock solution: 0.2M 1 liter
Maleic acid (MW = 121.14) 23.2 gm
+ ddH<sub>2</sub>0 to make 1 liter
Adjust pH with 0.1M Na0H. Dilute with ddH<sub>2</sub>0 to desired molarity.
G. Imidazole Buffer pH 6.2-7.8
Imidazole 0.2M = 13.62/1
C<sub>3</sub>H<sub>4</sub>N<sub>2 (MW = 68.08)
Adjust 0.2N HC1 to imidazole solution until desired pH is reached. Dilute to desired molarity with ddH<sub>2</sub>0.
H. AMPd Buffer pH 7.8-9.7
2-amino-methyl-1,3-propanediol 0.2M = 21.03 gm/1
C<sub>4</sub>H<sub>11</sub>NO<sub>2 (MW = 105.14)
Add 0.2M HC1 until desired pH is reached. Dilute with ddH<sub>2</sub>0 to desired molarity.
Preparation of pH buffer solutionsThe different names for phosphate salts. Standardization buffers pH 4 and pH 7. Ph range of
some buffer systems. Making up buffer solutions by adding an adjuster solution (acid or base) to a known volume and concentration of a primary salt solution. Potassium hydrogen phosphate,
potassium dihydrogen phosphate, disodium hydrogen phosphate, potassium hydrogen phthalate, sodium acetate,sodium tetraborate, tris aminomethane.
Related link:Analysis Buffers For EDTA titrationsFor Fluoride (TISAB)For Determination of Fe.
On this page: Click the links below to jump to the relevant info:
The preparation of pH buffer solutions acetate buffers phosphate buffers
solid mixture buffers
Phosphates
Phosphate salts are known by several names and the correct phosphate must be used to prepare buffer solutions.
One phosphate cannot be substituted for another phosphate. Check formula of salt to be certain.
Formula Name of salt Other names
KH2PO4potassium dihydrogen
phosphate
potassium dihydrogen orthophosphatemonobasic potassium phosphatemonopotassium phosphateacid potassium phosphatepotassium biphosphate
K2HPO4potassium hydrogen
phosphate
dipotassium hydrogen orthophosphatedipotassium hydrogen phosphatedibasic potassium phosphatedipotassium phosphate
K3PO4 potassium phosphatetribasic potassium phosphatetripotassium phosphate
Standardization buffersFor pH=7.00 :Add 29.1 ml of 0.1 molar NaOH to 50 ml 0.1 molar potassium dihydrogen phosphate.
Alternatively :Dissolve 1.20g of sodium dihydrogen phosphate and 0.885g of disidium hydrogen phosphate in 1 liter volume distilled water.
For pH= 4.00 :Add 0.1 ml of 0.1 molar NaOH to 50 ml of 0.1 molar potassium hydrogen phthalate .
Alternatively : Dissolve 8.954g of disodium hydrogen phosphste.12 H2O and 3.4023g of potassium dihydrogen phosphate in 1 liter volume distilled water.
Range of common buffer systems ¹
Buffering systemUseful buffering pH
range @ 25°C
Hydrochloric acid/ Potassium chloride 1.0 - 2.2
Glycine/ Hydrochloric acid 2.2 - 3.6
Potassium hydrogen phthalate/ Hydrochloric acid 2.2 - 4.0
Citric acid/ Sodium citrate 3.0 - 6.2
Sodium acetate/ Acetic acid 3.7 - 5.6
Potassium hydrogen phtaalate/ Sodium hydroxide 4.1 - 5.9
Disodium hydrogen phthalate / Sodium dihydrogen orthophospate
5.8 - 8.0
Dipotassium hydrogen phthalate / Potassium dihydrogen orthophospate
5.8 - 8.0
Potassium dihydrogen orthophosphate / sodium hydroxide
5.8 - 8.00
Barbitone sodium / Hydrochloric acid 6.8 - 9.6
Tris (hydroxylmethyl) aminomethane / Hydrochloric acid
7.0 - 9.00
Sodium tetraborate/ Hydrochloric acid 8.1 - 9.2
Glycine/ Sodium hydroxide 8.6 - 10.6
Sodium carbonate/ Sodium hydrogen carbonate 9.2 - 10.8
Sodium tetraborate/ Sodium hydroxide 9.3 - 10.7
Sodium bicarbonate / Sodium hydroxide 9.60 - 11.0
Sodium hydrogen orthophosphate / Sodium hydroxide
11.0 - 11.9
Potassium chloride/ Sodium hydroxide 12.0 - 13.0
Preparing a Buffer Solution ²
This page gives tabulated info on the preparation of buffers by mixing adjusters with a known volume of the primary salt solution.
BUFFERS 1.00 - 9.00
Buffer A :pH 1.0 - 2.2
Buffer B : pH 2.2 - 4.00
Buffer C : pH 4.10 - 5.90
Buffer D : pH 5.8 - 8.00
Buffer E : pH 7.0 - 9.00
50 ml 0.2 M KCl + mls of 0.2 M HCl
100 ml 0.1 M potassium hydrogen phthalate + mls of 0.1 M HCl.
100 ml 0.1 M potassium hydrogen phthalate + mls of 0.1 M NaOH
. 100 ml 0.1 M KH2PO4 + mls of 0.1 M NaOH.
100 ml 0.1 M tris (hydroxymethyl) aminomethane + mls of 0.1 M HCl.
pH mls of 0.2M HCl added
pH mls of 0.1M HCl added
pH mls of 0.1M NaOH added
pH mls of 0.1M NaOH added
pH mls of 0.1 M HCl added
1.00 134.0 2.20 99.0 4.10 2.6 5.80 7.2 7.00 93.2
1.10 105.6 2.30 91.6 4.20 6.0 5.90 9.2 7.10 91.4
1.20 85.0 2.40 84.4 4.30 9.4 6.00 11.2 7.20 89.4
1.30 67.2 2.50 77.6 4.40 13.2 6.10 13.6 7.30 86.8
1.40 53.2 2.60 70.8 4.50 17.4 6.20 16.2 7.40 84.0
1.50 41.4 2.70 64.2 4.60 22.2 6.30 19.4 7.50 80.6
1.60 32.4 2.80 57.8 4.70 27.2 6.40 23.2 7.60 77.0
1.70 26.0 2.90 51.4 4.80 33.0 6.50 27.8 7.70 73.2
1.80 20.4 3.00 44.6 4.90 38.8 6.60 32.8 7.80 69.0
1.90 16.2 3.10 37.6 5.00 45.2 6.70 38.6 7.90 64.0
2.00 13.0 3.20 31.4 5.10 51.0 6.80 44.8 8.00 58.4
2.10 10.2 3.30 25.8 5.20 57.6 6.90 51.8 8.l0 52.4
2.20 7.8 3.40 20.8 5.30 63.2 7.00 58.2 8.20 45.8
3.50 16.4 5.40 68.2 7.10 64.2 8.30 39.8
3.60 12.6 5.50 73.2 7.20 69.4 8.40 34.4
3.70 9.0 5.60 77.6 7.30 74.0 8.50 29.4
3.80 5.8 5.70 81.2 7.40 78.2 8.60 24.4
3.90 2.8 5.80 84.6 7.50 82.2 8.70 20.6
4.00 0.2 5.90 87.4 7.60 85.6 8.80 17.0
7.70 88.4 8.90 14.0
7.80 90.6 9.00 11.4
7.90 92.2
8.00 93.4
BUFFERS 08 - 13
Buffer F: pH 8.0 - 9.10
Buffer G : pH 9.2 - 10.80
Buffer H : pH 9.60 - 11.00
Buffer I : pH 10.90 - 12.00
Buffer J : pH 12.00 - 13.00
100 mL 0.025 M Na2B4O7.10H2O (borax) + mls of 0.1 M HCl.
100 mL 0.025 M Na2B4O7.10H2O (borax) + mls of 0.1 M NaOH.
100 mL 0.05 M NaHCO3 + mls of 0.1 M NaOH.
100 mL 0.05 M Na2HPO4 + mls of 0.1 M NaOH.
50 mL 0.2 M KCl + volume indicated (in mL) 0.2 M NaOH.
pH mls of 0.1M HCl added
pH mls of 0.1M NaOH added
pH mls of 0.1M NaOH added
pH mls of 0.1M NaOH added
pH mls of 0.2M NaOH added
8.00 41.0 9.20 1.8 9.60 10.0 10.90 6.6 12.00 12.0
8.10 39.4 9.30 7.2 9.70 12.4 11.00 8.2 12.10 16.0
8.20 37.6 9.40 12.4 9.80 15.2 11.10 10.2 12.20 20.4
8.30 35.4 9.50 17.6 9.90 18.2 11.20 12.6 12.30 25.6
8.40 33.2 9.60 22.2 10.00 21.4 11.30 15.2 12.40 32.4
8.50 30.4 9.70 26.2 10.10 24.4 11.40 18.2 12.50 40.8
8.60 27.0 9.80 30.0 10.20 27.6 11.50 22.2 12.60 51.2
8.70 23.2 9.90 33.4 10.30 30.4 11.60 27.0 12.70 64.4
8.80 19.2 10.00 36.6 10.40 33.0 11.70 32.4 12.80 82.4
8.90 14.2 10.10 39.0 10.50 35.6 11.80 38.8 12.90 106.0
9.00 9.2 10.20 41.0 10.60 38.2 11.90 46.0 13.00 132.0
9.10 4.0 10.30 42.6 10.70 40.4 12.00 53.8
10.40 44.2 10.80 42.4
10.50 45.4 10.90 44.0
10.60 46.6 11.00 45.4
10.70 47.6
10.80 48.5
Acetate buffer solutions pH 3 - 6 ³
Make up the following solutions(1) 0.1M acetic acid
(2) 0.1M sodium acetate (tri-hydrate) (13.6g / l)Mix in the following proportions to get the required ph
phvol. of 0.1Macetic acid
vol. of 0.1Msodium acetate
3 982.3 mls 17.7 mls
4 847.0 mls 153.0 mls
5 357.0 mls 643.0 mls
6 52.2 mls947.8 mls
Phosphate buffer solutions ph 7 - 11
Make up the following solutions(1) 0.1M disodium hydrogen phosphate (14.2g / l)
(2) 0.1M HCl(3) 0.1M NaOH
Mix in the following proportions to get the required ph
ph vol. of phosphate vol. of 0.1M HCl vol. of 0.1M NaOH
7 756.0 mls 244 mls
8 955.1 mls 44.9 mls
9 955.0 mls 45.0 mls
10 966.4 mls 33.6
11 965.3 mls 34.7
Addition of acid or base to a salt pH 3 - 11
Here, the primary salt is a solid and is weighed out in grams. A measured amount of 0.1M HCl or NaOH is added,
then made up to 1 liter to give the relevant buffer solution 4.
pHSalt mixture
Dilute each mixture to 1 liter solution with distilled water
3 10.21g potassium hydrogen phthalate and 223ml of 0.10M HCl
4 10.21g potassium hydrogen phthalate and 1ml of 0.10M HCl
5 10.21g potassium hydrogen phthalate and 226ml of 0.10M NaOH
6 6.81g potassium dihydrogen phOsphate and 56ml of 0.10M NaOH
7 6.81g potassium dihydrogen phosphate and 291ml of 0.10M NaOH
8 6.81g potassium dihydrogen phosphate and 467ml of 0.10M NaOH
9 4.77g sodium tetraborate and 46ml of 0.10M HCl
10 4.77g sodium tetraborate and 183ml of 0.10M NaOH
11 2.10g sodium bicarbonate and 227ml of 0.10M NaOH
1. The Physical and Theoretical Laboratory, Oxford University.2. "Electrolyte solutions" Robinson, R. A., and Stokes, R. H., 2nd ed., rev. London, Butterworths, 1968.3. "Practical chemistry" J. Lambert and T.A. Muir, 3rd. Ed. Heineman, London.4. pdf file, www.bc.ca/bcsc/resources/ (Canadian Teachers Federation).
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Versi hanya teksBerikut adalah frasa penelusuran yang disorot: amylase
MEDIA, REAGENTS AND SOLUTIONS
REAGENTS
The following reagents are used in the Microbiological Analyses Section of this Volume and are referenced in that Section. The listing is alphabetical.
Brilliant green solution
Brilliant green dye, sterile: 0.1 gDistilled water, sterile: 100 ml
On day of use, add 20 ml I2-KI solution and 10 ml brilliant green solution to 1 litre base. Re-suspend precipitate by gentle agitation and aseptically dispense 10 ml portions into 20 x 150 or 16 x 150 mm sterile test tubes. Do not heat medium after addition of I2-KI and dye solutions.
Bromcresol Purple Dye Solution (0.2%)
Bromcresol purple dye: 0.2 gSterile distilled water: 100 ml
Butterfield's Phosphate-Buffered Dilution Water
KH2PO4: 34 gDistilled water: 500 ml
Adjust pH to 7.2 with 1 N NaOH. Bring volume to 1 liter with distilled water. Sterilize 15 min at 121°. Store in refrigerator.
Dilution blanks
Take 1.25 ml of above stock solution and bring volume to 1 litre with distilled water. Dispense into bottles to 90 or 99 ± 1 ml. Sterilize 15 min at 121°.
Cellulase Solution
Dissolve 1 g cellulase in 99 ml sterile distilled water. Filter sterilize through a 0.45 μm filter. Cellulase solution may be stored at 2-5° for 2 weeks.
Chlorine Solution (200 ppm)
Commercial bleach (5.25% sodium hypochlorite): 8 mlDistilled water containing 1 g sodium dodecyl sulphate: 992 ml
Dissolve 1 g sodium dodecyl sulfate in 992 ml distilled water. Add 8 ml commercial bleach and mix well. Make immediately before use.
Ethanol Solution (70%)
Ethanol (95%): 700 mlDistilled water: add to final volume of 950 ml
Formalinized Physiological Saline Solution
Formaldehyde solution (36-38%): 6 mlNaCl: 8.5 gDistilled water: 1 litre
Dissolve 8.5 g NaCl in 1 liter distilled water. Autoclave 15 min at 121°. Cool to room temperature. Add 6 ml formaldehyde solution. Do not autoclave after addition of formaldehyde.
Hydrochloride Solution (1 N)
HCl (concentrated): 89 mlDistilled water to make 1 litre
Kovac's Reagent
p-Dimethylaminobenzaldehyde: 5 gAmyl alcohol (normal only): 75 mlHCl (concentrated): 25 ml
Dissolve p-dimethylaminobenzaldehyde in normal amyl alcohol. Slowly add HC1. Store at 4°. To test for indole, add 0.2-0.3 ml reagent to 5 ml of 24 h bacteria culture in tryptone broth. Dark red colour in surface layer is positive test for indole. For enteropathogenic E. coli, also test at 72 h if negative at 24 h.
Lysostaphin Solution
Dissolve 2.5 mg of lysostaphin in 0.02M phosphate-saline buffer containing 1 % NaCl.
Methyl Red Indicator
Methyl red: 0.1 gEthanol (95%): 300 mlDistilled water to make 500 ml
Nonfat dry milk
Nonfat dry milk: 100gDistilled water: 1 litre
For Salmonella:
Suspend 100 g dehydrated nonfat dry milk in 1 liter distilled water. Swirl until dissolved. Autoclave 15 min at 121°.
Papain
Papain: 5 gDistilled water: 1 litre
Add papain to sterile, distilled water and swirl to dissolve completely. Dispense 100 ml portion into bottles.
Physiological Saline Solution Sterile (0.85%)
NaCl: 8.5 gDistilled water: 1 litre
Dissolve 8.5 g NaCl in water. Autoclave 15 min at 121°. Cool to room temperature.
Potassium Hydroxide Solution (40%)
KOH: 40 gDistilled water to make 100 ml
Sodium Hydroxide Solution (1 N)
NaOH: 40 gDistilled water to make 1 litre
Voges-Proskauer (VP) Test Reagents
Solution 1
alpha-Naphthol: 5 gAlcohol (absolute): 100 ml
Solution 2
Potassium hydroxide: 40 gDistilled water to make 100 ml
Voges-Proskauer (VP) test. At room temperature, transfer 1 ml of 48 h culture to test tube and add 0.6 ml solution 1 and 0.2 ml solution 2. Shake after adding each solution. To intensify and speed reaction, add a few creatine crystals to mixture. Read results 4 h after adding reagents. Development of eosin pink colour is a positive.
BUFFER SOLUTIONS
Buffer Test Solutions
Buffer TS (pH 2)
Combine 11.90 ml of 0.2 M hydrochloric acid and 88.10 ml of 0.2 M potassium chloride, and dilute to 200 ml with water.
Buffer TS (pH 5)
Add 51.5 ml of 0.2 M disodium hydrogen phosphate to 48.5 ml of 0.1 M citric acid.
Buffer TS (pH 5.45)
Dissolve 1.8360 g of citric acid and 3.198 g of disodium hydrogen phosphate in carbon dioxide-free water to make 200 ml.
Buffer TS (pH 6.5)
Combine 50 ml of 0.2 M potassium dihydrogen phosphate and 15.2 ml of 0.2 M sodium hydroxide, and dilute to 200 ml with water.
Buffer acetate TS (pH 5.0)
Add 4.6 g of anhydrous sodium acetate to 11.6 ml of 2 M acetic acid and dilute to 200 ml with water. Adjust the pH to 5.0 ±0.1 with glacial acetic acid or 10% sodium hydroxide solution.
Barbital buffer solution (pH 7.6)
Dissolve 4.3 g of barbital sodium in 200 ml of water, adjust the pH to 7.6 with dilute hydrochloric acid, and filter.
Citric acid buffer solution
Dissolve 21 g of citric acid in water to make 1,000 ml (Solution A). Dissolve 28.4 g of disodium hydrogen phosphate in water to make 1,000 ml (Solution B). Combine 11 volumes of Solution A and 389 volumes of Solution B.
Formic acid buffer solution (pH 2.5)
Add 18 ml of water to 0.8 ml of formic acid, adjust the pH to 2.5 with strong ammonia TS, and dilute to 200 ml with water.
Phosphate buffer solution (pH 7.0)
Combine 50 ml of 0.2 M potassium dihydrogen phosphate and 29.54 ml of 0.2 M sodium hydroxide, and dilute to 200 ml with water.
Phosphate buffer solution (pH 7.3-7.4) (0.02M)
Stock solution 1:
Sodium phosphate dibasic anhydrous: 28.4 gNaCl: 85 gDistilled water: 1 litre
Stock solution 2:
Sodium phosphate monobasic monohydrate: 27.6 gNaCl: 85 gDistilled water: 1 litre
Make 1:10 dilutions of each stock solution. For example:
Stock solution 1 50 ml Stock solution 2 10 ml
Distilled water 450 ml Distilled water 90 ml
Approximate pH 8.2 Approximate pH 5.6
Using a pH meter, titer diluted solution1 to pH 7.3-7.4 by adding about 65 ml of solution 2. Use the resulting 0.02 M phosphate saline buffer solution in the lysostaphin susceptibility test on S. aureus.
Note: Do not titer 0.2 Mphosphate buffer to pH 7.3-7.4 and then dilute to 0.02 Mstrength. This results in a drop in pH of approximately 0.25. Addition of 0.85% salt after pH adjustment also results in a drop of approximately 0.2.
Phosphate buffer solution (pH 7.5)
Dissolve 53.7 g of disodium hydrogen phosphate in water to make 1,000 ml (Solution A). Dissolve 20.4 g of potassium dihydrogen phosphate in water to make 1,000 ml (Solution B). Combine 21 volumes of Solution A and 4 volumes of Solution B, and adjust the pH to 7.5 with either Solution A or Solution B.
Standard Buffer Solutions
Reagent Solutions
Previously dry the crystalline reagents (except for boric acid), at 110° to 120°, and use water that has been previously boiled and cooled to prepare the solutions. Store the prepared reagent solutions in chemically resistant glass or polyethylene bottles, and use within 3 months. Discard if moulding is evident.
Boric acid/potassium chloride, 0.2 M
Dissolve 12.366 g of boric acid (H3BO3) and 14.911 g of potassium chloride (KC1) in water to make 1,000 ml.
Hydrochloric acid, 0.2 M
Dilute 19 ml of hydrochloric acid with water to make 1,000 ml and standardize the solution as follows: dissolve about 0.3 g, accurately weighed, of primary standard anhydrous sodium carbonate (Na2CO3), previously dried at about 270° for 1 h in 100 ml of water. Titrate with the hydrochloric acid using 2 drops of methyl red TS. When the solution becomes faintly pink, boil to expel carbon dioxide, cool, and continue the titration until the faint pink colour is no longer affected by continued boiling. Each 10.60 mg of Na2CO3 is equivalent to 1 ml of 0.2 M hydrochloric acid.
Potassium chloride, 0.2 M
Dissolve 14.911 g of potassium chloride (KC1) in water to make 1,000 ml.
Potassium hydrogen phthalate, 0.2 M
Dissolve 40.844 g of potassium hydrogen phthalate [KHC6H4(COO)2] in water to make 1,000 ml.
Potassium dihydrogen phosphate, 0.2 M
Dissolve 27.218 g of potassium dihydrogen phosphate (KH2PO4) in water to make 1,000 ml.
Sodium hydroxide, 0.2 M
Dissolve about 9 g of sodium hydroxide (NaOH) in about 950 ml of water, and add a freshly prepared saturated solution of barium hydroxide until no more precipitate forms. Shake the mixture thoroughly, and allow it to stand overnight in a stoppered bottle. Decant or filter the solution, and standardize the clear liquid as follows: Dissolve about 1 g, accurately weighed, of primary standard potassium hydrogen phthalate [KHC6H4(COO)2], previously dried at 105° for 3 h in 75 ml of carbon dioxide-free water, and titrate with the sodium hydroxide solution to a permanent pink colour using 2 drops of phenolphthalein TS, as indicator. Each 40.84 mg of KHC6H4(COO)2 is equivalent to 1 ml of 0.2 M sodium hydroxide.
Composition of Standard Buffer Solutions
To prepare a standard buffer solution having a pH within the range 1.2 to 10.0, combine the appropriate solutions, prepared above, as shown in the following table, and dilute with water to make 200 ml. The standard pH values given in this table are considered to be reproducible to within ± 0.02 of the pH unit specified at 25°.
Hydrochloric Acid Buffer
Acid Phthalate Buffer
Neutralized Phthalate
Buffer
Phosphate Buffer
Alkaline Borate Buffer
To 50.0 ml of 0.2 M KCl add the specified ml of 0.2MHC1
To 50.0 ml of 0.2 M KHC6H4-(COO)2 add the specified ml of 0.2MHC1
To 50.0 ml of 0.2 M KHC6H4 -(COO)2 add the specified ml of 0.2 M NaOH
To 50.0 ml of 0.2 M KH2PO4 add the specified ml of 0.2 M NaOH
To 50.0 ml of 0.2 M H3BO3KCl add the specified ml of 0.2 M NaOH
pH ml pH ml pH ml pH ml pH ml
1.2 85.0 2.2 49.5 4.2 3.0 5.8 3.6 8.0 3.9
1.3 67.2 2.4 42.2 4.4 6.6 6.0 5.6 8.2 6.0
1.4 53.2 2.6 35.4 4.6 11.1 6.2 8.1 8.4 8.6
1.5 41.4 2.8 28.9 4.8 16.5 6.4 11.6 8.6 11.8
1.6 32.4 3.0 22.3 5.0 22.6 6.6 16.4 8.8 15.8
1.7 26.0 3.2 15.7 5.2 28.8 6.8 22.4 9.0 20.8
1.8 20.4 3.4 10.4 5.4 34.1 7.0 29.1 9.2 26.4
1.9 16.2 3.6 6.3 5.6 38.8 7.2 34.7 9.4 32.1
2.0 13.0 3.8 2.9 5.8 42.3 7.4 39.1 9.6 36.9
2.1 10.2 4.0 0.1 7.6 42.4 9.8 40.6
2.2 7.8 7.8 44.5 10.0 43.7
8.0 46.1
STANDARD SOLUTIONS
Ammonium Standard Solution
Dissolve 296.0 mg of ammonium chloride, NH4C1, in sufficient water to make 100 ml. Transfer 10.0 ml of this solution into a 1,000-ml volumetric flask, dilute to volume with water. Each ml of this solution contains 0.01 mg of NH+
4.
Barium Standard Solution
Dissolve 177.9 mg of barium chloride, BaCl2.2H20, in water in a 1,000-ml volumetric flask, dilute to volume with water, and mix. Each ml of this solution contains 0.1 mg of Ba.
Barium Chloride Standard Solution
Dissolve 4.3 g of barium chloride in sufficient water to make 1,000 ml. Perform gravimetric analysis on the solution, and calculate the quantity of sodium sulfate (Na2SO4) corresponding to 1 ml of the solution. Each ml of this solution corresponds to about 2.5 mg of Na2SO4.
Chromium Standard Solution
To 0.934 g of potassium chromate, add 1 drop of 10% sodium hydroxide solution and water to 1,000 ml. To a 1.0 ml portion of the solution, add 1 drop of 10% sodium hydroxide solution and water to 1,000 ml. Each ml of this solution contains 0.25 μg of Cr.
Condensed Formaldehyde Standard Solution
Dilute 8.1 g of formalin (containing 37% of HCHO) with water to 1,000 ml. To a 10.0 ml portion of the solution, add water to 1,000 ml. Each ml of this solution contains 0.03 mg of HCHO. Prepare freshly before use.
Dithizone Standard Solution
Dissolve 10 mg of dithizone in 1,000 ml of chloroform. Store in a stoppered bottle lead free and in a cold place.
Formaldehyde Standard Solution
Dilute 2.7 g of formalin (containing 37% of HCHO) with water to 1,000 ml. To a 10 ml portion of the solution, add water to 1,000 ml. Each ml of this solution contains 0.01 mg of HCHO. Prepare the solution fresh.
Iron Standard Solution
Dissolve 8.63 g of ferric ammonium sulfate in 20 ml of dilute nitric acid, and add water to 1,000 ml. To 10 ml of the solution add 20 ml of dilute nitric acid and water to 1,000 ml. Each ml of this solution contains 0.01 mg of Fe. Store in a dark bottle.
Lead Standard Solution
Dissolve 159.8 mg of lead nitrate in 10 ml of dilute nitric acid, and add water to 1,000 ml. Prepare and store this solution in lead-free glassware. Dilute 10 ml of the solution with water to 100 ml. Each ml of this solution contains 0.01 mg of Pb. Prepare the solution fresh.
Lead Standard Solution for Dithizone test
To 10 ml of lead standard solution, add 1% nitric acid to 100 ml. Each ml of this solution contains 1 μg of Pb. Prepare the solution fresh.
Magnesium Standard Solution
Dissolve 50.0 mg magnesium metal, Mg, in 1 ml of hydrochloric acid in a 1,000-ml volumetric flask, dilute to volume with water, and mix. Each ml of this solution contains 0.05 mg Mg.
Mercury Standard Solution
Dissolve 0.135 g of mercuric chloride in 10 ml of dilute nitric acid and sufficient water to make 1,000 ml. Dilute 10 ml of the solution with 10 ml of dilute nitric acid and water to make 1,000 ml. Dilute the second solution in same manner. Each ml of this final solution contains 0.1 μg of Hg in 1 ml. Prepare the solution fresh.
Methanol Standard Solution
To 5 ml of 0.1% methanol, add 2,5 ml of ethyl alcohol not containing methanol, and add water to 50 ml. Each ml of this solution contains 0.1 mg of CH3OH.
Nitrate Standard Solution
Dissolve 1.63 g of potassium nitrate in water to make 1,000 ml. To a 10 ml portion of the solution, add water to 100 ml. Each ml of this solution contains 0.1 mg of NO3.
Phosphate Standard Solution
Dissolve 143.3 mg of monobasic potassium phosphate, KH2PO4, in water in a 100 ml volumetric flask, dilute to volume with water, and mix. Transfer 10.0 ml of this solution into a 1,000-ml volumetric flask, dilute to volume with water, and mix. Each ml of this solution contains 10 μg phosphate.
Potassium Phosphate, Monobasic, Standard Solution
Dissolve 4.394 g of potassium phosphate monobasic in sufficient water to make 1,000 ml. Each ml of this solution contains 1 mg of phosphate.
Selenium Standard Solution
Add 10 ml of dilute sulfuric acid (1 in 2) to 1 g of selenium. Heat to dissolve, and evaporate to dryness on a water bath. Dissolve the residue in sufficient water to make 1,000 ml. To a 10
ml portion of the solution, add water to 1,000 ml. Each ml of this solution contains 0.01 mg of Se.
Thiamine Hydrochloride Standard Solution
Dissolve 0.1 g of vitamin B1 hydrochloride reference standard previously dried at 105° for 2 h, in water to make 1,000 ml. To a 10 ml portion of the solution, add water to 1,000 ml. Each ml of this solution contains 1 μg of vitamin B1 hydrochloride reference standard.
Zinc Standard Solution
Dissolve 4.4 g of zinc sulfate in water to make 1,000 ml. To a 10 ml portion of the solution, add water to 1,000 ml. Each ml of this solution contains 0.01 mg of Zn.
TEST SOLUTIONS
Potassium Hydroxide TS
A 6.5% w/v solution of potassium hydroxide (KOH) in water (approximately N).
Potassium Hydroxide TS, Ethanolic
Place a few g (5 to 10) of potassium hydroxide in a 2-litre flask, add 1 to 1.5 L of 95% ethanol and boil on a water bath under reflux condenser from 30 to 60 min. Distil and collect the ethanol. Dissolve 40 g of potassium hydroxide, low in carbonate, in 1,000 ml of the distilled ethanol keeping the temperature below 15.5° while the alkali is being dissolved. This solution should remain clear.
Potassium Iodate TS
A 0.71% w/v solution of potassium iodate in water. Preserve in the dark.
Potassium Iodide TS
A 16.5% w/v solution of potassium iodide (KI) in water (approximately N). Store in a light-resistant container.
Potassium Permanganate TS
A 1.0% w/v solution of potassium permanganate (KMnO4) in water
paperThe juice will be used to run two sub sample determinations of starch on each clone. Starch will be measured using the rapid SPRI iodometric method with minor modifications. Juice (3 ml) will be transferred to two test tubes and placed in a boiling water bath for 10 minutes to completely solubilize the starch. After boiling, the juice will be cooled on ice. After cooling, 2N acetic acid (1.2 ml), 10 % KI (0.25 ml) and KIO3 (2.5 ml) will be added in that order
1. Individual Chemicals and Products List (formerly the Master ... Jenis Berkas: PDF/Adobe AcrobatBAN 360MG (ALPHA AMYLASE). 9157. BAND-ADE SAWING FLUID ...... HYDROCHLORIC ACID,YTTRIUM SALT,KI,KIO3, +. 11338. HYDROCINNAMIC ACID ...www.drs.illinois.edu/css/guidesplans/wasteguide/.../appendixA.pdf - Mirip
2. Full text of "Practical physiological chemistry: A Book Designed ... - [ Terjemahkan laman ini ] Experiments on Enzymes' 1. amylases 1. Demonstration of Salivary Amylase. 4 — To 25 cc of a 1 per cent starch paste in a small beaker, add 5 drops of saliva ... www.archive.org/stream/.../practicalphysio00hawkgoog_djvu.txt - Mirip
A buffer solution resists changes in pH when acids or bases are added or when dilution occurs. ...
The accuracy of Sigma-Aldrich analytical buffer solutionsis ensured by careful choice of the buffer substances, the useof deionized water with extremely low conductivity andsubsequent calibration of the pH value with standard buffersolutions to DIN 19266.
Promotion only available with the Promotion Code T03 until 31<sup>st August 2009 (European Customers only)
Product No. DescriptionAdd to Cart
31044-1L Buffer solution pH 1.0 (20°C) hydrochloric acid / potassium chloride 31045-1L Buffer solution pH 2.0 (20°C) citric acid / hydrochloric acid / sodium chloride 31046-1L Buffer solution pH 3.0 (20°C) citric acid / sodium hydroxide / sodium chloride 31103-1L Acetate buffer solution pH 4.65 sodium acetate / acetic acid 33544-1L Buffer solution pH 5.0 (20°C) citric acid / sodium hydroxide 33545-1L Buffer solution pH 6.0 (20°C) citric acid / sodium hydroxide 33547-1L Buffer solution pH 8.0 (20°C) borax / hydrochloric acid 33552-1L Buffer solution pH 13.0 (20°C) glycine / sodium hydroxide / sodium chloride 33582-1L Ammonia buffer solution for complexometry, ammonium chloride / ammonia, pH 10 33643-1L Buffer solution pH 4.0 (20°C) citric acid / sodium hydroxide / sodium chloride 33643-100ML
Buffer solution pH 4.0 (20°C) citric acid / sodium hydroxide / sodium chloride
33643-500ML
Buffer solution pH 4.0 (20°C) citric acid / sodium hydroxide / sodium chloride
33643-5L-VP Buffer solution pH 4.0 (20°C) citric acid / sodium hydroxide / sodium chloride 33643-10L-VP
Buffer solution pH 4.0 (20°C) citric acid / sodium hydroxide / sodium chloride
33646-1LBuffer solution pH 7.0 (20°C) potassium dihydrogen phosphate / disodium hydrogen phosphate
33646-100ML
Buffer solution pH 7.0 (20°C) potassium dihydrogen phosphate / disodium hydrogen phosphate
33646-500ML
Buffer solution pH 7.0 (20°C) potassium dihydrogen phosphate / disodium hydrogen phosphate
33646-5L-VPBuffer solution pH 7.0 (20°C) potassium dihydrogen phosphate / disodium hydrogen phosphate
33646-10L-VP
Buffer solution pH 7.0 (20°C) potassium dihydrogen phosphate / disodium hydrogen phosphate
33648-1L Buffer solution pH 9.0 (20°C) borax / hydrochloric acid 33648-100ML
Buffer solution pH 9.0 (20°C) borax / hydrochloric acid
33648-500ML
Buffer solution pH 9.0 (20°C) borax / hydrochloric acid
33648-5L-VP Buffer solution pH 9.0 (20°C) borax / hydrochloric acid 33648-10L-VP
Buffer solution pH 9.0 (20°C) borax / hydrochloric acid
33649-1L-R Buffer pH 10.00 borax / sodium hydroxide solution 33649-100ML-R
Buffer pH 10.00 borax / sodium hydroxide solution
33649-500ML-R
Buffer pH 10.00 borax / sodium hydroxide solution
33650-1L-RBuffer solution pH 11.0 (20°C) boric acid / sodium hydroxide solution / potassium chloride
33650-100ML-R
Buffer solution pH 11.0 (20°C) boric acid / sodium hydroxide solution / potassium chloride
33650-500ML-R
Buffer solution pH 11.0 (20°C) boric acid / sodium hydroxide solution / potassium chloride
33651-1L Buffer solution pH 12.0 (20°C) di-sodium hydrogen phosphate / sodium hydroxide 33651-100ML
Buffer solution pH 12.0 (20°C) di-sodium hydrogen phosphate / sodium hydroxide solution
82563-1L Buffer solution pH 1.0 (20°C) hydrochloric acid ~0.13 M, potassium chloride ~0.050 M 82563-50ML Buffer solution pH 1.0 (20°C) hydrochloric acid ~0.13 M, potassium chloride ~0.050 M
82564-1LBuffer solution pH 2.0 (20°C) hydrochloric acid ~0.0082 M, citric acid ~0.03 M, sodium chloride ~0.061 M
82564-50MLBuffer solution pH 2.0 (20°C) hydrochloric acid ~0.0082 M, citric acid ~0.03 M, sodium chloride ~0.061 M
82565-1LBuffer solution pH 3.0 (20°C) citric acid ~0.040 M, sodium hydroxide ~0.021 M, sodium chloride ~0.060 M
82565-50MLBuffer solution pH 3.0 (20°C) citric acid ~0.040 M, sodium hydroxide ~0.021 M, sodium chloride ~0.060 M
82566-1LBuffer solution pH 4.0 (20°C) citric acid ~0.056 M, sodium hydroxide ~0.068 M, sodium chloride ~0.044 M, sodium azide ~0.05 %
82566-50MLBuffer solution pH 4.0 (20°C) citric acid ~0.056 M, sodium hydroxide ~0.068 M, sodium chloride ~0.044 M, sodium azide ~0.05 %
82567-1L Buffer solution pH 5.0 (20°C) citric acid ~0.096 M, sodium hydroxide ~0.20 M 82567-50ML Buffer solution pH 5.0 (20°C) citric acid ~0.096 M, sodium hydroxide ~0.20 M 82568-1L Buffer solution pH 6.0 (20°C) citric acid ~0.060 M, sodium hydroxide ~0.16 M 82568-50ML Buffer solution pH 6.0 (20°C) citric acid ~0.060 M, sodium hydroxide ~0.16 M
82571-1LBuffer solution pH 7.0 (20°C) sodium hydroxide solution ~0.029 M, potassium dihydrogen phosphate ~0.050 M
82571-50MLBuffer solution pH 7.0 (20°C) sodium hydroxide solution ~0.029 M, potassium dihydrogen phosphate ~0.050 M
82573-1L Buffer solution pH 8.0 (20°C) hydrochloric acid ~0.021 M, borax ~0.013 M 82573-50ML Buffer solution pH 8.0 (20°C) hydrochloric acid ~0.021 M, borax ~0.013 M 82574-1L Buffer solution pH 9.0 (20°C) borax ~0.013 M, hydrochloric acid ~0.0046 M 82574-50ML Buffer solution pH 9.0 (20°C) borax ~0.013 M, hydrochloric acid ~0.0046 M 82575-1L Buffer solution pH 10.0 (20°C) sodium hydroxide ~0.018 M, borax ~0.013 M 82575-50ML Buffer solution pH 10.0 (20°C) sodium hydroxide ~0.018 M, borax ~0.013 M
82576-1LBuffer solution pH 11.0 (20°C) glycine ~0.051 M, sodium hydroxide ~0.049 M, sodium chloride ~0.051 M
82638-1L Buffer solution according to Soerensen pH 6.5 Back to Top
Buffer Solutions, pH 1 - 4
Product #
Description
36050Acetate buffer solution pH 4.65 sodium acetate / acetic acid, solution ready for use
31103Acetate buffer solution pH 4.65 sodium acetate / acetic acid, solution ready for use
33581Acetate buffer solution pH 4.6 for complexometry, sodium acetate / acetic acid, solution ready for use
82563Buffer solution pH 1.0 (20 °C) potassium chloride ~0.050 M, hydrochloric acid ~0.13 M
31044Buffer solution pH 1.0 (20 °C) hydrochloric acid / potassium chloride, solution ready for use
82564Buffer solution pH 2.0 (20 °C) hydrochloric acid ~0.0082 M, citric acid ~0.03 M, sodium chloride ~0.061 M
456098Buffer solution pH 2.0 (20°C)
33541Buffer solution pH 2.0 (20 °C) citric acid / hydrochloric acid / sodium chloride, solution ready for use, with fungicide
31045Buffer solution pH 2.0 (20 °C) citric acid / hydrochloric acid / sodium chloride, solution ready for use, with fungicide
82565Buffer solution pH 3.0 (20 °C) sodium hydroxide ~0.021 M, citric acid ~0.040 M, sodium chloride ~0.060 M
33542Buffer solution pH 3.0 (20 °C) citric acid / sodium hydroxide / sodium chloride solution, solution ready for use, with fungicide
31046Buffer solution pH 3.0 (20 °C) citric acid / sodium hydroxide / sodium chloride solution, solution ready for use, with fungicide
82566Buffer solution pH 4.0 (20°C) sodium azide ~0.05 %, sodium hydroxide ~0.068 M, citric acid ~0.056 M, sodium chloride ~0.044 M
33643Buffer solution pH 4.0 (20 °C) with fungicide, citric acid / sodium hydroxide / sodium chloride solution, solution ready for use
CATATAN;
BUFFER SITRAT DAPAT DIBUAT DENGAN CARA1. DARI ASAM SITRAT DAN SODIUM SITRAT2. DARI SODIUM SITRAT DAN HCl
CONTOH : BUFFER 0.2 M Na- SITRAT / HCl pH 4.5 (0.2 M sodium citrate/HCl buffer pH 4.5)
Dikutip D.L.Bartel Internet Feb05
PBS UNTUK IMUNOHISTOKIMIA
0.5M PB (PHOSPHATE BUFFER) STOCK
106.5 g dibasic sodium phosphate (anhydrous) 34.5 g monobasic sodium phosphate ( anhydrous)
Add the above to 1800 mL distilled water. Bring the final volume to 2 L. When the salts have gone into solution, adjust the pH with sodium hydroxide to between 7.2 - 7.4 This stock is kept at room temperature and is good for several weeks.
5M NaCl
292.2 g NaCl
Add the above to 800 mL distilled water. Bring final volume to 1 L. Let stir thouroughly until salt has completely dissolved. This stock is kept at room temperature and is good for several weeks.
0,1 M PBS (working soluion for immuno)
200 mL 0.5M PB stock final PB concentration 0.1 M 30 mL 5M NaCl stock final NaCl concentration 150 mM 770 mL distilled water
1 L PBS for immnuno washes