TECH TIP #68
Protein assay compatibility table
TR0068.5
Introduction
No single protein assay method is compatible with all sample components that might be encountered in typical laboratory
research. To alleviate the frustration of discovering these incompatibilities by trial and error, our technical support scientists
have characterized the effects of commonly used buffers and sample components on the behavior of seven different Thermo
Scientific Pierce* Protein Assays.
Results of these compatibility experiments are summarized in tabular form on the following two pages. The table serves as a
guide for assessing which protein assay(s) might be most effective with a given sample type. Use this information as a guide
only. It is the researcher’s responsibility to validate the compatibility of specific sample buffers. Even minor changes in
buffers and components affect each assay method to some extent. Researchers must decide if these effects are acceptable for
their specific purposes.
About the Compatibility Table
The table indicates the maximum compatible concentrations for
substances tested with the Test Tube procedure on the midpoint
concentration of BSA standard (i.e., 1000µg/mL for most
assays; 10µg/mL for the Micro BCA Assay). Substances were
considered compatible at the indicated concentration if the error
in protein concentration estimation caused by the presence of
the substance in the sample was less than or equal to 10%.
Tested Thermo Scientific Pierce Protein Assays.
Notes and Symbols:
•
•
•
•
•
•
•
•
•
Part No.
Name
22662
660 nm
23225
BCA
23235
Micro BCA
23250
BCA – Reducing Agent Compatible (BCA-RAC)
23252
Microplate BCA-RAC
23240
Modified Lowry
23236
Coomassie Plus (Bradford)
23200
Coomassie (Bradford)
Compounds are listed alphabetically using common names or abbreviations, except sodium compounds which are alphabetized under “Na”.
Dilutions are expressed as “neet” (= undiluted) or in the form of a ratio, where “1:2” means 2-fold dilution.
n/a Denotes that the compound was not tested in this assay.
Ø Denotes compounds that were not compatible at the lowest concentration tested.
* Thermo Scientific product trademark; “PER Reagents” are Thermo Scientific Pierce Cell Lysis Reagents.
** Trademarks that are the property of other companies; see end of document.
† Value when the 660nm Assay is run using the ionic detergent compatibility reagent (IDCR, Part No. 22663).
†† Selected values for the regular BCA-RAC Kit are given in parentheses in the column for the Microplate BCA-RAC.
‡ Compound (buffer) whose formulation is described more fully in the following table:
Part No.
28390
28374
28382
28388
28386
28372
89900
28379
28380
28378
28398
Buffer
Formulation
2-D sample buffer
Laemmli SDS sample buffer
MES-buffered saline pH 4.7
Modified Dulbecco’s PBS
Na carb-bicarb pH 9.4
Na citrate-carbonate pH 9
Na citrate-MOPS pH 7.5
Phosphate-buffered saline (PBS)
RIPA Buffer
Tris-buffered saline (TBS)
Tris-glycine pH 8.0
Tris-glycine-SDS pH 8.3
Tris-HEPES-SDS
(8M urea, 4% CHAPS) or (7M urea, 2M thiourea, 4% CHAPS)
65mM Tris-HCl, 10% glycerol, 2% SDS, 0.025% bromophenol blue
0.1M MES, 150mM NaCl pH 4.7
8mM sodium phosphate, 2mM potassium phosphate, 0.14M NaCl, 10mM KCl, pH 7.4
0.2M sodium carbonate-bicarbonate pH 9.4
0.6M sodium citrate, 0.1M sodium-carbonate pH 9
0.6M sodium citrate 0.1M MOPS pH 7.5
100mM sodium phosphate, 150mM NaCl pH 7.2
50mM Tris, 150mM NaCl, 0.5% DOC, 1% NP40, 0.1% SDS pH 8.0
25mM Tris, 150mM NaCl pH 7.6
25mM Tris, 192mM glycine pH 8.0
25mM Tris, 192mM glycine, 0.1% SDS pH 8.3
100mM Tris, 100mM HEPES, 3mM SDS
Pierce Biotechnology
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(815) 968-0747
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Rockford, lL 61105 USA
(815) 968-7316 fax
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Thermo Scientific Pierce Protein Assay
Test Compound
660 nm
BCA
Micro BCA
††Microplate
BCA-RAC
Coomassie
Plus
Coomassie
Modified
Lowry
2-D sample buffer ‡
2-Mercaptoethanol
ACES, pH 7.8
Acetone
Acetonitrile
Ammonium sulfate
Aprotinin
Ascorbic acid
Asparagine
Bicine
Bis-Tris pH 6.5
Borate (50mM) pH 8.5
B-PER* Reagent
B-PER Reagent II
B-PER Reagent PBS
Brij**-35
Brij-56
Brij-58
Bromophenol blue (in 50mM NaOH)
Calcium chloride (in TBS pH 7.2)
Cesium bicarbonate
Cetylpyridinium chloride
CHAPS
CHAPSO
CHES
Cobalt chloride (in TBS pH 7.2)
CTAB
Cysteine
Dithioerythritol (DTE)
Dithiothreitol (DTT)
DMF
DMSO
DTAB
EDTA
EGTA
EPPS pH 8.0
Ethanol
Ferric chloride (in TBS pH 7.2)
Glucose
Glutathione (reduced)
Glycerol (fresh)
Glycine-HCl pH 2.8
Guanidine-HCl
HEPES pH 7.5
Hydrides (Na2BH4 or NaCNBH3)
Hydrochloric acid (HCl)
Imidazole pH 7.0
I-PER* Reagent
Laemmli SDS sample buffer ‡
Leupeptin
Mannitol
Melibiose
Mem-PER* Reagent
MES-buffered saline pH 4.7 ‡
MES pH 6.1
Methanol
Magnesium chloride
Modified Dulbecco's PBS ‡
MOPS pH 7.2
M-PER* Reagent
neet
1M
50mM
50%
50%
125mM
2mM
500mM
40mM
>1M
50mM
neet
1:2
1:2
1:2
5%
n/a
5%
0.031%
40mM
100mM
2.5% †
5%
4%
>500mM
20mM
2.5% †
350mM
25mM
500mM
50%
50%
2% †
20mM
20mM
200mM
50%
5mM
500mM
100mM
50%
100mM
2.5M
100mM
Ø
125mM
200mM
1:4
neet †
80µM
100mM
500mM
neet
neet
125mM
50%
>1M
neet
125mM
1:2
n/a
0.01%
25mM
10%
10%
1.5M
10mg/L
Ø
1mM
20mM
33mM
neet
neet
n/a
n/a
5%
1%
1%
Ø
10mM
100mM
n/a
5%
5%
100mM
0.8mM
n/a
Ø
1mM
1mM
10%
10%
n/a
10mM
Ø
100mM
10%
10mM
10mM
n/a
10%
100mM
4M
100mM
Ø
100mM
50mM
neet
Ø
10mg/L
n/a
Ø
neet
neet
100mM
10%
n/a
neet
100mM
neet
n/a
1mM
10mM
1%
1%
Ø
1mg/L
Ø
n/a
2mM
0.2mM
1:4
n/a
n/a
n/a
5%
1%
1%
Ø
10mM
100mM
n/a
1%
5%
100mM
Ø
n/a
Ø
Ø
Ø
1%
1%
n/a
0.5mM
Ø
100mM
1%
0.5mM
1mM
n/a
1%
n/a
4M
100mM
Ø
10mM
12.5mM
n/a
Ø
10mg/L
n/a
n/a
neet
1:4
100mM
1%
n/a
neet
100mM
n/a
n/a
25mM (35)
Ø
Ø
30%
Ø
Ø
n/a
Ø
1mM
16.5mM
Ø
1:3
1:4
1:4
0.63%
n/a
0.50%
Ø
1mM
Ø
n/a
10% (10)
Ø
50mM
0.4mM
n/a
2.5mM
2.5mM
5mM (5)
5%
0.25%
n/a
5mM (20)
5mM (10)
Ø
Ø
5mM
Ø
10mM
5%
50mM
1.5M (2)
200mM (200)
n/a
Ø
30mM (50)
n/a
Ø
Ø
n/a
n/a
1:2
Ø
100mM (100)
0.5%
100mM
neet
200mM
1:2
n/a
1M
100mM
10%
10%
1M
10mg/L
50mM
10mM
100mM
100mM
neet
1:2
1:4
n/a
0.062%
0.031%
0.016%
Ø
10mM
100mM
n/a
5%
5%
100mM
10mM
n/a
10mM
1mM
5mM
10%
10%
n/a
100mM
2mM
100mM
10%
10mM
1M
n/a
10%
100mM
3.5M
100mM
n/a
100mM
200mM
n/a
Ø
10mg/L
n/a
100mM
neet
neet
100mM
10%
n/a
neet
100mM
neet
n/a
1M
100mM
10%
10%
1M
10mg/L
50mM
10mM
100mM
100mM
neet
1:2
n/a
n/a
0.125%
0.031%
0.031%
Ø
10mM
100mM
n/a
5%
5%
100mM
10mM
n/a
10mM
1mM
5mM
10%
10%
n/a
100mM
2mM
100mM
10%
10mM
1M
n/a
10%
100mM
3.5M
100mM
n/a
100mM
200mM
n/a
Ø
10mg/L
n/a
100mM
n/a
neet
100mM
10%
n/a
neet
100mM
n/a
n/a
1mM
n/a
10%
10%
Ø
10mg/L
1mM
5mM
n/a
n/a
n/a
n/a
n/a
n/a
0.031%
0.062%
0.062%
Ø
n/a
50mM
n/a
0.062%
0.031%
n/a
n/a
n/a
1mM
Ø
Ø
10%
10%
n/a
1mM
1mM
n/a
10%
n/a
100mM
n/a
10%
100mM
n/a
1mM
n/a
100mM
25mM
n/a
Ø
10mg/L
n/a
25mM
n/a
n/a
125mM
10 %
n/a
n/a
n/a
n/a
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PO Box 117
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(815) 968-7316 fax
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Thermo Scientific Pierce Protein Assay
Continued…
Test Compound
n-Acetylglucosamine
Na acetate pH 4.8
Na azide
Na bicarbonate
Na carb-bicarbonate pH 9.4 ‡
Na chloride
Na citrate pH 4.8
Na citrate-carbonate pH 9 ‡
Na citrate-MOPS pH 7.5 ‡
Na deoxycholate (DOC)
Na hydroxide (NaOH)
Na phosphate
NE-PER* Reagent (CER)
NE-PER Reagent (NER)
Nickel chloride (in TBS pH 7.2)
NP-40
Octyl beta-glucoside
Octylthioglucoside
Na-orthovanadate (in PBS pH 7.2)
Phenol Red
Phosphate-buffered saline (PBS) ‡
PIPES pH 6.8
PMSF in isopropanol
Potassium thiocyanate
P-PER Reagent
RIPA buffer ‡
SDS
Sodium compounds
Span** 20
Sucrose
TCEP
Thimerosal
Thiourea
TLCK
TPCK
T-PER* Reagent
Tricine pH 8.0
Triethanolamine pH 7.8
Tris-buffered saline (TBS) ‡
Tris-glycine pH 8.0 ‡
Tris-glycine-SDS pH 8.3 ‡
Tris-HCl pH 8.0
Tris-HEPES-SDS ‡
Triton** X-100
Triton X-114
Triton X-305
Triton X-405
Tween** 20
Tween 60
Tween 80
Urea
Y-PER* Reagent
Y-PER Plus Reagent
Zinc chloride (in TBS pH 7.2)
Zwittergent** 3-14
660 nm
100mM
100mM
0.125%
100mM
1:3
1.25M
12.5mM
Ø
1:16
0.25%
125mM
500mM
neet
neet
10mM
5%
5%
10%
50mM
0.5mg/mL
neet
100mM
1mM
250mM
1:2
neet
0.01%, 5% †
(see Na)
n/a
50%
40mM
0.25%
2M
5mg/mL
4mg/mL
1:2
500mM
100mM
neet
neet
neet †
250mM
neet †
1%
0.50%
9%
5%
10%
5%
5%
8M
Ø
1:2
10mM
0.05%
BCA
10mM
200mM
0.2%
100mM
neet
1M
200mM
1:8
1:8
5%
100mM
100mM
neet
neet
10mM
5%
5%
5%
1mM
Ø
neet
100mM
1mM
3M
Ø
neet
5%
(see Na)
1%
40%
Ø
0.01%
n/a
0.1mg/L
0.1mg/L
1:2
25mM
25mM
neet
1:3
neet
250mM
n/a
5%
1%
1%
1%
5%
5%
5%
3M
neet
neet
10mM
1%
Micro BCA
Ø
200mM
0.20%
100mM
neet
1M
5mM
1:600
1:600
5%
50mM
100mM
n/a
n/a
0.2mM
5%
0.1%
5%
1mM
Ø
neet
100mM
1mM
n/a
n/a
1:10
5%
(see Na)
1%
4%
Ø
Ø
n/a
0.1mg/L
0.1mg/L
n/a
2.5mM
0.5mM
1:10
1:10
neet
50mM
n/a
5%
0.05%
1%
1%
5%
0.5%
5%
3M
n/a
n/a
0.5mM
Ø
††Microplate
BCA-RAC
Ø
Ø
0.01%
Ø
neet
150mM
50mM
Ø
neet
n/a
Ø
100mM
1:2
1:4
Ø
Ø
2.5% (10)
7%
0.5mM
3.125µg/mL
neet
25mM
0.125mM
Ø
1:2
1:2
5% (10)
(see Na)
n/a
40% (40)
10mM (10)
0.03%
n/a
Ø
Ø
n/a
0.5mM
25mM
neet
Ø
Ø
35mM (50)
n/a
7% (10)
2% (2)
1%
Ø
10% (10)
5%
2.5%
3M (4)
n/a
n/a
Ø
2% (2)
Coomassie
Plus
100mM
180mM
0.5%
100mM
neet
5M
200mM
neet
n/a
0.4%
100mM
100mM
1:4
neet
10mM
0.5%
0.5%
3%
1mM
0.5mg/mL
neet
100mM
1mM
3M
Ø
1:40
0.016%
(see Na)
0.5%
10%
125mM
0.01%
n/a
0.1mg/mL
0.1mg/mL
neet
100mM
100mM
neet
neet
1:4
2M
n/a
0.062%
0.062%
0.125%
0.025%
0.031%
0.025%
0.016%
3M
n/a
neet
10mM
0.025%
Coomassie
100mM
180mM
0.5%
100mM
neet
5M
200mM
neet
neet
0.05%
100mM
100mM
n/a
n/a
10mM
0.5%
0.5%
3%
1mM
0.5mg/mL
neet
100mM
1mM
3M
Ø
1:10
0.125%
(see Na)
0.5%
10%
125mM
0.01%
n/a
0.1mg/L
0.1mg/L
n/a
100mM
100mM
neet
neet
1:2
2M
n/a
0.125%
0.125%
0.5%
0.5%
0.062%
0.1%
0.062%
3M
n/a
n/a
10mM
0.025%
Modified
Lowry
n/a
200mM
0.2%
100mM
n/a
1M
n/a
n/a
n/a
n/a
100mM
100mM
n/a
n/a
n/a
0.016%
0.031%
n/a
n/a
n/a
n/a
n/a
1mM
100mM
Ø
n/a
1%
(see Na)
0.25%
7.5%
n/a
0.01%
n/a
0.01mg/L
0.1mg/L
n/a
n/a
n/a
n/a
n/a
n/a
10mM
n/a
0.031%
0.031%
0.031%
0.031%
0.062%
n/a
0.031%
3M
n/a
n/a
n/a
n/a
Triton® is a registered trademark of Rohm & Haas Co.
Brij®, Tween® and Span® are registered trademarks of ICI Americas.
Zwittergent® is a registered trademark of American Hoechst Corporation.
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© 2012 Thermo Fisher Scientific Inc. All rights reserved. Unless otherwise indicated, all trademarks are property of Thermo Fisher Scientific Inc. and its
subsidiaries. Printed in the USA.
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PO Box 117
(815) 968-0747
3747 N. Meridian Road
Rockford, lL 61105 USA
(815) 968-7316 fax
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