Bovine Serum Albumin (BSA Protein)

Supplementation of cell culture media with BSA protein can benefit cell growth and survival, especially when using serum-free media. Bovine serum albumin binds essential molecules present in the media (e.g., fatty acids, hormones, peptides), allowing for efficient delivery of these molecules into cultured cells. The antioxidative properties of BSA protein can also reduce cellular stress and damage.

Thermo Fisher Scientific offers a variety of Gibco BSA products optimized for supplementing cell culture media, including AlbuMAX Lipid-Rich BSA, which can reduce or eliminate the need for supplementation of cell culture media with serum.

BSA protein is also commonly used for blocking during immunoassays, including ELISA and western blotting. As a single protein, BSA is less likely to exhibit cross-reactivity with antibodies than milk, which is a complex protein mixture. In addition, BSA protein, which is generally unphosphorylated, is often recommended for assays involving anti-phosphoprotein antibodies. Anti-phosphoprotein antibodies may nonspecifically bind phosphorylated proteins found in milk blockers (i.e., casein). However, anti-phosphoprotein antibodies are unlikely to bind BSA, reducing background.

Blocker BSA in PBS and Blocker BSA in TBS are both available from Thermo Fisher Scientific as valuable additions to your immunoassay protocols.

Thermo Fisher Scientific offers bovine serum albumin conjugated to fluorescent tags, which can be used for tracer studies in combination with anti-BSA antibodies. In addition, BSA fluorescent conjugates can be used in quantitative studies of electroporation, and also to measure plasma in rats.