蛋白浓度测定BCA法

The amount listed is the maximum amount of material allowed in the protein sample without causing a noticeable interference, when 20 ul protein sample is used for BCA assay as described in the standard assay.

Incompatible Substances / Amount Compatible

Buffer Systems

N-Acetylglucosamine (10 mM) in PBS, pH 7.2 10 mM

ACES, pH 7.8 25 mM

Bicine, pH 8.4 20 mM

Bis-Tris, pH 6.5 33 mM

CelLytic B Reagent undiluted, no interference

Calcium chloride in TBS, pH 7.2 10 mM

CHES, pH 9.0 100 mM

Cobalt chloride in TBS, pH 7.2 0.8 M

EPPS, pH 8.0 100 mM

Ferric chloride in TBS, pH 7.2 10 mM

HEPES 100 mM

MOPS, pH 7.2 100 mM

Nickel chloride in TBS 10 mM

PBS; Phosphate (0.1 M),

NaCl (0.15 M), pH 7.2 undiluted, no interference

PIPES, pH 6.8 100 mM

Sodium acetate, pH 4.8 200 mM

Sodium citrate, pH 4.8 or pH 6.4 200 mM

Tricine, pH 8.0 25 mM

Triethanolamine, pH 7.8 25 mM

Tris 250 mM

TBS; Tris (25 mM), NaCl (0.15 M), pH 7.6 undiluted, no interference

Tris (25 mM), Glycine (1.92 M), SDS (0.1%), pH 8.3, undiluted, no interference

Zinc chloride (10 mM) in TBS, pH 7.2, 10 mM

Buffer Additives

Ammonium sulfate 1.5 mM

Aprotinin 10 mg/L

Cesium bicarbonate 100 mM

Glucose 10 mM

Glycerol 10%

Guanidine•HCl 4 M

Hydrochloric acid 100 mM

Imidazole 50 mM

Leupeptin 10 mg/L

PMSF 1 mM

Sodium azide 0.20%

Sodium bicarbonate 100 mM

Sodium chloride 1 M

Sodium hydroxide 100 mM

Sodium phosphate 25 mM

Sucrose 40%

TLCK 0.1 mg/L

TPCK 0.1 mg/L

Sodium ortho-Vanadate in PBS, pH 7.2, 1 mM

Thimerosal 0.01%

Urea 3 MChelating agents

EDTA 10 mM

EGTA not compatible

Sodium citrate 200 mM

Detergents

Brij-35 5%

Brij-52 1%

CHAPS 5%

CHAPSO 5%

Deoxycholic acid 5%

Nonidet P-40 (Igepal CA-630) 5%

Octyl ®-glucoside 5%

Octyl ®-thioglucopyranoside 5%

SDS 5%

Span 20 1%

Triton X-100 5%

Triton X-114 1%

Triton X-305 1%

Triton X-405 1%

Tween 20 5%

Tween 60 5%

Tween 80 5%

X-Dodecyl 1%

Zwittergents 1%

Reducing & Thiol Containing Agents

Dithioerythritol (DTE) 1 mM

Dithiothreitol (DTT) 1 mM

2-Mercaptoethanol 1 mM

Tributyl Phosphine 0.01%

Solvents

Acetone 10%

Acetonitrile 10%

DMF 10%

DMSO 10%

Ethanol 10%

Methanol 10%

Note: This is not a complete compatibility chart. There are many substances that can affect different proteins in different ways. One may assay the protein of interest in deionized water alone, then in the buffer with possible interfering substances. Comparison of the readings will indicate if an interference exists.

Note: Reagents that chelate metal ions, change the pH of the assay, or reduce copper will interfere with the BCA assay. Examples are shown below:

1. Metal chelators such as EDTA (> 10 mM) and EGTA (any level).

2. Thiol containing reagents such as cysteine (any level), DTT (> 1 mM), dithioerythritol(> 1 mM), and 2-mercaptoethanol (> 0.01%).

3. High salt or buffers concentrations such as ammonium sulfate (> 1.5 M), Tris (>0.25 M), and sodium phosphate (> 0.1 M).