Accurately quantifying total protein concentration is a key to most experiments and is often necessary for isolation, separation, and analysis of proteins by biochemical methods. When it is necessary to determine the total protein concentration in a sample, one of the first factors to consider is the selection of a protein assay method. The choice among available protein assays typically is based upon the compatibility of the method with the samples to be assayed. We offer assay reagents, kits and standards to determine total protein concentration of samples containing different buffer components for protein quantitation using both fluorescence-based and colorimetric assays.
Protein assay selection guide
No one reagent can be considered to be the ideal or best protein assay method. Each method has its advantages and disadvantages. Use the chart below to help select the best protein assay for your application based on the sample composition and your preferred method.
|No detergents or reducing agents||Colorimetric||BCA Assays||Coomassie™ Plus (Bradford) Assay|
|Fluorescent||Quant-iT™ Protein Assay Kit||Qubit® Protein Assay Kit|
(but not reducing agents)
|Colorimetric||BCA Assays||600nm Protein Assay||Detergent Compatible Bradford Assay|
|Fluorescent||CBQCA Protein Quantitation Kit||EZQ™ Protein Quantitation Kit|
(but not detergents)
|Colorimetric||BCA-Reducing Agent Compatible Assay Kits||600nm Protein Assay||Coomassie™ (Bradford) Assay|
|Fluorescent||NanoOrange® Protein Quantitation Assay||EZQ™ Protein Quantitation Kit|
|Both detergents and reducing agents||Colorimetric||BCA-Reducing Agent Compatible Assay Kits||600nm Protein Assay||Detergent Compatible Bradford Assay|
|Fluorescent||EZQ™ Protein Quantitation Kit|
We offer high-quality, easy-to-use protein standard solutions to serially dilute to create assay standard curves to measure protein concentration
- Bovine Serum Albumin (BSA) Standards—ideal for measuring total protein concentration
- Bovine Gamma Globulin (BGG) Standards—ideal for measuring total protein concentration in samples containing antibody (IgG)
We have developed specialized protein assay reagents and kits to estimate and measure specific post-translational modification (PTM) or functional (enzymatic) classes of proteins in biological samples, including glycoproteins and phosphoproteins.
- Glycoprotein Carbohydrate Estimation Kit—measure protein glycosylation as the percent of purified protein mass compared to included glycoprotein standards; uses periodic acid Schiff-base reagents (PAS).
- Phosphoprotein Phosphate Estimation Assay Kit—classify and identify proteins as phosphorylated (serine and threonine) and obtain semi-quantitative assessment of the phosphorylation levels.
We offer various colorimetric and fluorescent reagents to accomplish pre-column and post-column derivatization of peptides and amino acids for analysis by HPLC detectors; includes vacuum hydrolysis tubes and quantitation standards.
For Research Use Only. Not for use in diagnostic procedures.