Measuring protein concentration

Accurately quantifying total protein concentration is a key step in most experiments and workflows involving isolation, separation, and analysis of proteins by biochemical methods. The choice among available protein assays typically is based upon several factors, including its chemical compatibility with buffer components of the samples to be assayed. We offer a variety of assay reagents, kits and standards for protein quantitation by fluorescent or colorimetric detection with fluorometers, spectrophotometers, and plate readers.

Use the interactive Protein Assay Selection Guide to compare multiple protocol variants and parameters among all protein and peptide assays products.


Featured protein assay categories

Colorimetric Protein Assays

Evaluate features of Pierce BCA protein assay kits, Bradford reagents and kits (Coomassie dye-based), Pierce 660 nm kits, and Lowry kits for colorimetric determination of sample protein concentration by protein-copper chelation or protein-dye binding methods.

Fluorescent Protein Assays

Evaluate features of the Quant-iT Protein Assay, Qubit assay kits, NanoOrange assay, CBQCA assay, and EZQ assay for fluorescent determination of sample protein concentration using different excitation/emission wavelengths and fluorometer types.

Standards for Protein Assays

High-quality, easy-to-use protein standard solutions, which can be serially diluted to create assay standard curves in protein assays to measure protein concentration. Choose Bovine Serum Albumin (BSA) Standards for mixed protein samples or Bovine Gamma Globulin (BGG) Standards to for predominantly immunoglobulin samples.


Additional protein assay categories

Easy-to-use colorimetric or fluorescent peptide assays that are designed specifically to improve the sensitivity and reproducibility of quantitation of peptide mixtures.

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.

Easy-to-use colorimetric or fluorescent peptide assays that are designed specifically to improve the sensitivity and reproducibility of quantitation of peptide mixtures.

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.