Bovine serum albumin (also known as BSA) is a serum albumin protein derived from cows, which is often used as a protein concentration standard in lab experiments. Among its 583 amino acid residues, it contains 17 intrachain disulfide bonds as well as one free thiol group, which can be used for site-specific labeling with a thiol-reactive (maleimide) fluorescent dye. Tris(2-carboxyethyl)phosphine (TCEP) is a widely used reducing agent for the reduction of disulfide bonds on proteins. High TCEP concentrations and/or long incubation times can impair the structural integrity of BSA by reducing structurally important intrachain disulfide bonds.

structural integrity | reducing agents | TCEP | PR-P-016