Buffer Reference Center

Buffer Reference Center

• pH Ranges of Selected Biological Buffers Chart (25 °C, 0.1 M)

• Tris or Trizma® Buffer Preparation – pH vs. Temperature

• Phosphate Buffer Preparation – 0.2 M solution

• Citric Acid – Na₂HPO₄ Buffer Preparation, pH 2.6-7.6

• Citric Acid – Sodium Citrate Buffer Preparation, pH 3.0-6.2

• Sodium Acetate – Acetic Acid Buffer Preparation, pH 3.7-5.6

• Na₂HPO₄ – NaH₂2PO₄ Buffer Preparation, pH 5.8-8.0 at 25 °C

• Imidazole (glyoxaline) – HCl Buffer Preparation, pH 6.2-7.8 at 25 °C

• Sodium Carbonate – Sodium Bicarbonate Buffer Preparation, pH 9.2-10.8

• Buffer Preparation Formulas and Equations

CHOOSING THE RIGHT BIOLOGICAL BUFFER

Choose a buffer based on your pH requirements as well as the pKa, a measure of acid strength that accounts for pH, concentration, and temperature. Regulatory or purity needs for your exact application should also be considered. The following tables can help you navigate preparation of many common buffer solutions by pH and pKa.

Buffer Level

Buffer grade indicates the quality and impurity levels appropriate for different uses. We provide six grades of buffers indicated for general lab use, final pharmaceutical formulation and manufacturing, and applications in between that may need trace metal testing or materials of a specified purity.

USEFUL PH RANGES OF SELECTED BIOLOGICAL BUFFERS CHART (25 °C, 0.1 M)

Buffers	Useful pH Range	pKa（20℃）	pKa（25℃）	pKa（37℃）	Reagent Grade	Higher Grade
MES	5.5-6.7	6.16	6.1	5.97	M105074	M274288
Bis-Tris	5.8-7.2	n/a	6.5	6.36	B105639	B113072
ADA	6.0-7.2	6.65	6.59	6.46	A108964	A108965
ACES	6.1-7.5	6.88	6.78	6.54	A100327	A100328
PIPES	6.1-7.5	6.8	6.76	6.66	P105090	P105092
					P105093	P105091
MOPSO	6.2-7.6	n/a	6.9	6.75	M113008	n/a
Bis-Tris-Propane	6.3-9.5	n/a	6.8，9.0	n/a	B299299	n/a
					B105640
BES	6.4-7.8	7.17	7.09	6.9	B105116	B105117
					B105115
MOPS	6.5-7.9	7.28	7.2	7.02	M105135	M274252
					M105133
TES	6.8-9.2	7.5	7.4	7.16	T105113	T105114
HEPES	6.8-8.2	7.55	7.48	7.31	H109407	H109408
					H109406
DIPSO	7.0-8.2	n/a	7.6	7.35	B113022	n/a
MOBS	6.9-8.3	n/a	7.6	n/a	M120630	n/a
TAPSO	7.0-8.2	n/a	7.6	7.39	T113029	n/a
Tris	7.0-9.0	8.2	8.06	7.72	T110600	T110602
						T110599
						T110598
						T274227
						T274250
						T110601
HEPPSO	7.1-8.5	n/a	7.8	6.66	H113003	n/a
POPSO	7.2-8.5	n/a	7.8	7.63	P105272	n/a
TEA	7.3-8.3	n/a	7.8	n/a	T108151	n/a
					T108154
EPPS	7.3-8.7	n/a	8	n/a	H110899	H110901
					H110900
Tricine	7.4-8.8	8.16	8.05	7.8	T100351	T118067
					T100350
Gly-gGly	7.5-8.9	n/a	8.2	n/a	G105429	G119491
						G119492
						G119491
Bicine	7.6-9.0	8.35	8.26	8.04	B110905	B110906
HEPBS	7.6-9.0	n/a	8.3	n/a	H113002	n/a
TAPS	7.7-9.1	8.49	8.4	8.18	T108961	T108963
					T108962
AMPD	7.8-9.7	n/a	8.8	n/a	A106026	n/a
TABS	8.2-9.6	n/a	8.9	n/a	T329718	n/a
AMPSO	8.3-9.7	n/a	9	9.1	A120640	n/a
CHES	8.6-10.0	9.55	9.49	9.36	C110897	n/a
					C110898
CAPSO	8.9-10.3	n/a	9.6	9.43	C105213	n/a
AMP	9.0-10.5	n/a	9.7	n/a	A140833	n/a
					A100592
CAPS	9.7-11.1	10.56	10.4	10.02	C105209	n/a
					C105210
CABS	10.0-11.4	n/a	10.7	n/a	C120628	n/a

TRIS BUFFER PREPARATION TABLE – PH VS. TEMPERATURE

pH at Temperature	 	 	g/L for 0.05M Solution
5℃	25℃	37℃	Tris-HCl	Tris base
7.76	7.2	6.91	7.02	0.67
7.89	7.3	7.02	6.85	0.8
7.97	7.4	7.12	6.61	0.97
8.07	7.5	7.22	6.35	1.18
8.18	7.6	7.3	6.06	1.39
8.26	7.7	7.4	5.72	1.66
8.37	7.8	7.52	5.32	1.97
8.48	7.9	7.62	4.88	2.3
8.58	8	7.71	4.44	2.65
8.68	8.1	7.8	4.02	2.97
8.78	8.2	7.91	3.54	3.34
8.88	8.3	8.01	3.07	3.7
8.98	8.4	8.1	2.64	4.03
9.09	8.5	8.22	2.21	4.36
9.18	8.6	8.31	1.83	4.65
9.28	8.7	8.42	1.5	4.9
9.36	8.8	8.51	1.23	5.13
9.47	8.9	8.62	0.96	5.32
9.56	9	8.7	0.76	5.47

PHOSPHATE BUFFER PREPARATION TABLE – 0.2 M SOLUTION

Potassium	Sodium Phosphate Dibasic Heptahydrate	23℃ pH	Potassium Phosphate Monobasic	Sodium Phosphate	23℃ pH
Phosphate Monobasic Anhydrous g/L	 	 	Anhydrous g/L	Dibasic Heptahydrate
22.4	3.49	5.7	10.8	29.51	6.9
22.08	4.29	5.8	9.36	32.73	7
21.6	5.37	5.9	7.92	35.95	7.1
21.05	6.6	6	6.72	38.63	7.2
20.4	8.05	6.1	5.52	41.31	7.3
19.56	9.93	6.2	4.56	43.46	7.4
18.6	12.07	6.3	3.84	45.07	7.5
17.64	14.22	6.4	3.12	46.68	7.6
16.44	16.9	6.5	2.52	48.55	7.7
15	20.12	6.6	2.04	49.09	7.8
13.56	23.34	6.7	1.68	49.89	7.9
12.24	26.29	6.8	1.27	50.81	8

CITRIC ACID – NA2HPO4 BUFFER PREPARATION, PH 2.6–7.6¹ 

Citric acid monohydrate, C₆H₈O₇ • H₂O, MW 210.14; 0.1 M contains 21.01 g/L. Na₂HPO₄, MW 141.98; 0.2 M contains 28.40 g/L, or Na₂HPO₄ • ₂H₂O, MW 178.05; 0.2 M contains 35.61 g/L.

x mL 0.1 M-citric acid and y mL 0.2 M-Na₂HPO₄ mixed

pH	X mL 0.1M-citric acid	Y mL 0.2M-Na2HPO4
2.6	89.1	10.9
2.8	84.15	15.85
3	79.45	20.55
3.2	75.3	24.7
3.4	71.5	28.5
3.6	67.8	32.2
3.8	64.5	35.5
4	61.45	38.55
4.2	58.6	41.4
4.4	55.9	44.1
4.6	53.25	46.75
4.8	50.7	49.3
5	48.5	51.5
5.2	46.4	53.6
5.4	44.25	55.75
5.6	42	58
5.8	39.55	60.45
6	36.85	63.15
6.2	33.9	66.1
6.4	30.75	69.25
6.6	27.25	72.75
6.8	22.75	77.25
7	17.65	82.35
7.2	13.05	86.95
7.4	9.15	90.85
7.6	6.35	93.65

CITRIC ACID – SODIUM CITRATE BUFFER PREPARATION, PH 3.0-6.2¹

Citric acid monohydrate, C₆H₈O₇ • H₂O, MW 210.14; 0.1 M contains 21.01 g/L. Trisodium citrate dihydrate, C₆H₅O₇Na₃ •2H₂O, MW 294.12; 0.1 M contains 29.41 g/L.

x mL 0.1 M-citric acid and y mL 0.1 M-trisodium citrate mixed

pH	X mL 0.1M-citric acid	Y mL 0.1M-trisodium citrate
3	82	18
3.2	77.5	22.5
3.4	73	27
3.6	68.5	31.5
3.8	63.5	36.5
4	59	41
4.2	54	46
4.4	49.5	50.5
4.6	44.5	55.5
4.8	40	60
5	35	65
5.2	30.5	69.5
5.4	25.5	74.5
5.6	21	79
5.8	16	84
6	11.5	88.5
6.2	8	92

SODIUM ACETATE – ACETIC ACID BUFFER PREPARATION, PH 3.7–5.6¹ 

Sodium acetate trihydrate, CH₃COONa • ₃H₂O, MW 136.09; 0.2 M contains 27.22 g/L.

x mL 0.2 M-NaOAc and y mL 0.2 M-HOAc mixed

pH，18℃	X mL 0.2M-NaOAc	Y mL 0.2M-HOAc
3.7	10	90
3.8	12	88
4	18	82
4.2	26.5	73.5
4.4	37	63
4.6	49	51
4.8	59	41
5	70	30
5.2	79	21
5.4	86	14
5.6	91	9

NA₂HPO₄ – NAH₂PO₄ BUFFER PREPARATION, PH 5.8-8.0 AT 25 °C¹ 

Na₂HPO₄• 2H₂O, MW 178.05; 0.2 M contains 35.61 g/L. Na₂HPO₄ • 12H₂O, MW 358.22; 0.2 M contains 71.64 g/L. NaH₂PO₄ • H₂O, MW 138.01; 0.2 M contains 27.6 g/L. NaH₂PO₄ • 2H₂O, MW 156.03; 0.2 M contains 31.21 g/L.

x mL 0.2 M-Na₂HPO₄, y mL 0.2 M-NaH₂PO₄; diluted to 100 mL with H₂O

pH，25℃	X mL 0.2M-Na2HPO4	Y mL 0.2M-NaH2PO4
5.8	4	46
6	6.15	43.85
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	30.5	19.5
7.2	36	14
7.4	40.5	9.5
7.6	43.5	6.5
7.8	45.75	4.25
8	47.35	2.65

IMIDAZOLE (GLYOXALINE) – HCL BUFFER PREPARATION, PH 6.2–7.8 AT 25 °C¹

Imidazole,C₃H₄N₂,, MW 68.08

25 mL 0.2 M-imidazole (13.62 g/L), x mL 0.2 M-HCl, diluted to 100 mL with H₂O

pH, 25℃	X mL 0.2M-HCl
6.2	21.45
6.4	19.9
6.6	17.75
6.8	15.2
7	12.15
7.2	9.3
7.4	6.8
7.6	4.65
7.8	3

SODIUM CARBONATE – SODIUM BICARBONATE BUFFER PREPARATION, PH 9.2-10.8¹

Na₂CO₃ • 10H₂O, MW 286.2; 0.1 M contains 28.62 g/L. NaHCO₃, MW 84.0; 0.1 M contains 8.40 g/L.

x mL 0.1 M-Na₂CO₃and y mL 0.1 M-Na₂HCO₃mixed

20℃	37℃
X mL 0.1M-Na2CO3	Y mL 0.1M-NaHCO3,
9.2	8.8
9.4	9.1
9.5	9.4
9.8	9.5
9.9	9.7
10.1	9.9
10.3	10.1
10.5	10.3
10.8	10.6

BUFFER PREPARATION FORMULAS AND EQUATIONS

Percentage by weight (w/v)

(% buffer desired / 100) × final buffer volume (mL) = g of starting material needed.

Molar Solutions

desired molarity × formula weight × solution final volume (L) = grams needed

Henderson-Hasselbach Equation

项目号	产品名称	规格	CAS编号	包装
M274288	MES Free Acid Monohydrate	Ultra Pure Grade	145224-94-8	100g/250g/500g/1kg/12x100g/12x250g/12x500g
M105074	MES monohydrate	≥99% (T)	145224-94-8	25g/100g/500g/2.5kg
B105639	BIS-TRIS	98%	6976-37-0	25g/100g/500g
B113072	BIS-TRIS	用于细胞和昆虫细胞培养, ≥98% (HPLC)	6976-37-0	25g/100g/500g
A108965	N-(2-Acetamido)iminodiacetic acid	Ultra Pure, ≥99.0% (T)	26239-55-4	25g/100g
A108964	N-(2-Acetamido)iminodiacetic acid	98%	26239-55-4	25g/100g/500g
A100327	N-(2-Acetamido)iminodiacetic acid	99%	7365-82-4	25g/100g/500g
A100328	N-(2-Acetamido)iminodiacetic acid	超纯级,≥99.5% (T)	7365-82-4	25g/100g
P105090	1,4-Piperazinediethanesulfonic acid(PIPES)	99%	5625-37-6	25g/100g/500g
P105093	1,4-Piperazinediethanesulfonic acid(PIPES)	99.5%	5625-37-6	25g/100g/500g
P105092	1,4-Piperazinediethanesulfonic acid(PIPES)	for cell culture,≥99%	5625-37-6	25g/100g/500g/1kg/2.5kg
M113008	3-(N-Morpholino)-2-hydroxy-1-propanesulfonic acid	99%	68399-77-9	25g/100g/500g/1kg
B299299	BIS-TRIS propane	98%	64431-96-5	5g/25g/100g/500g
B105640	BIS-TRIS propane	99%	64431-96-5	5g/25g/100g/500g
B105115	BES	≥99%(T)	10191-18-1	25g/100g/500g/1kg/2.5kg
B105116	BES	≥99.5%(T)	10191-18-1	25g/100g/250g
B105117	BES	用于分子生物学,≥99.5%(T)	10191-18-1	25g/100g/500g
T105114	TES	超纯级,≥ 99.5%(T)	7365-44-8	25g/100g/500g
T105113	TES	99%	7365-44-8	5g/25g/100g/500g
H109406	HEPES	99%	7365-45-9	25g/100g/500g/1kg/2.5kg
H109408	HEPES	用于分子生物学,≥99.5%(T)	7365-45-9	5g/25g/100g/500g
H109407	HEPES	≥99.5%(T)	7365-45-9	25g/100g/500g/1kg/5kg
B113022	3-[Bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid	98%	68399-80-4	25g/100g/500g
M120630	4-(N-Morpholino)butanesulfonic Acid	99%	115724-21-5	25g/100g
T113029	N-[Tris(hydroxymethyl)methyl]-3-amino-2-hydroxypropanesulfonic acid	99%	68399-81-5	25g/100g/500g
T274250	Tris(hydroxymethyl)aminomethane (TRIS, Trometamol)	超纯级	77-86-1	500g/1kg/5kg/10kg/12x500g
T110600	Tris(hydroxymethyl)aminomethane (TRIS, Trometamol)	ACS, ≥99.8%	77-86-1	25g/100g/500g
T110601	Tris(hydroxymethyl)aminomethane (TRIS, Trometamol)	分子生物学级,≥99.9%(T)	77-86-1	250g/1kg
T110599	Tris(hydroxymethyl)aminomethane (TRIS, Trometamol)	标准缓冲物质, ≥99.9% (titration)	77-86-1	100g/500g/1kg/5kg/10kg
T110602	Tris(hydroxymethyl)aminomethane (TRIS, Trometamol)	细胞培养级,≥99.9%(T)	77-86-1	100g/500g/1kg/5kg
T274227	Tris(hydroxymethyl)aminomethane (TRIS, Trometamol)	蛋白质组级	77-86-1	500g/1kg/12x500g/4x1kg
T110598	Tris(hydroxymethyl)aminomethane (TRIS, Trometamol)	EP, USP, 已细胞培养测试, ≥99.9% (T)	77-86-1	100g/500g/2.5kg
H113003	4-(2-Hydroxyethyl)piperazine-1-(2-hydroxypropanesulfonic acid) monohydrate	99%	68399-78-0	5g/25g/100g
P105272	Piperazine-1,4-bis(2-hydroxypropanesulfonic Acid) Dihydrate	99%	68189-43-5	25g/100g/500g/2.5kg
T108151	Triethanolamine	AR	102-71-6	100ml/500ml/2.5L
T108150	Triethanolamine	Standard for GC, ≥99.5% (GC)	102-71-6	5ml
T108153	Triethanolamine	色谱级，>99.0% (GC)	102-71-6	100ml/500ml
T108154	Triethanolamine	≥99.0% (GC)	102-71-6	100ml/500ml/2.5L
H110899	HEPPS	≥99.0%(T)	16052-06-5	5g/25g/100g/500g
H110901	HEPPS	用于细胞培养,≥99.5%(T)	16052-06-5	25g/100g/500g
T100351	Tricine	99.5%	5704-04-1	25g/100g/500g
T118067	Tricine	for cell culture,≥99.5%(T)	5704-04-1	25g/100g/500g/1kg
T100350	Tricine	99%	5704-04-1	25g/100g/500g
G105429	Gly-Gly	99%	556-50-3	5g/25g/100g/500g
G119491	Gly-Gly	超纯级, ≥99.5% (NT)	556-50-3	10g/50g
G119492	Gly-Gly	细胞培养级, ≥99% (titration)	556-50-3	25g/100g/500g
B110906	N,N-Bis(2-hydroxyethyl)glycine	超纯级，≥99.5% (T)	150-25-4	25g/100g/500g
B110905	N,N-Bis(2-hydroxyethyl)glycine	99%	150-25-4	25g/100g/500g
T108962	TAPS	≥99.5%(T)	29915-38-6	25g/100g/500g/5kg
T108963	TAPS	用于细胞培养级,≥99.5%(T)	29915-38-6	25g/100g/500g
T108961	TAPS	99%	29915-38-6	5g/25g/100g/500g
A106026	2-Amino-2-methyl-1,3-propanediol	98%	115-69-5	25g/100g
A120640	AMPSO	99%	68399-79-1	5g/25g/100g
C110898	CHES	≥99.0%(T)	103-47-9	5g/25g/100g/500g
C110897	CHES	≥99.5%(T)	103-47-9	25g/100g
C105213	CAPSO	99%	73463-39-5	25g/100g/500g/2.5kg
A100592	2-Amino-2-methyl-1-propanol	90%	124-68-5	25ml/100ml/500ml/2.5L
A140833	2-Amino-2-methyl-1-propanol	≥95%	124-68-5	25ml/100ml/500ml/2.5L
C105209	CAPS	≥98.0%	1135-40-6	25g/100g/500g/1kg/5kg
C105210	CAPS	超纯级, ≥99.0% (HPLC)	1135-40-6	25g/100g/500g

References

1. Dawson R, Elliot D, Elliot W, Jones KM. 1986. Data for Biochemical Research. 3rd ed.. Oxford Science Publ..