Ambion Ultrapure BSA is a “non-acetylated” BSA pure enough to use when DNA or RNA integrity is critical. Each tube containing 50mg is provided, at a concentration of 50mg/mL. Bovine Serum Albumin (BSA) has many uses as a carrier protein and as a stabilizing agent in enzymatic reactions. In northern, Southern, and dot blot hybridizations, BSA is also used as a blocking agent. It is recommended in buffers for nick translation, polymerase reactions, and ligations. BSA is also a common additive for PCR amplifications, footprinting, and gel shift assays. In restriction digests, BSA has been shown to enhance enzyme activity. The molecular weight is 68kD. Ultrapure BSA is rigorously tested for DNase, RNase, endonuclease, protease, peroxidase, and alkaline phosphatase activity, and assayed for fluorescence background. Exonuclease Activity: 3' - 5'.