This Diagnostic Grade BSA Powder is designed to minimize analytes that cause background interference. Accordingly, this BSA can be used for sensitive immunoassays, including ELISAs (Enzyme-Linked Immunosorbent assay), immunoblots and immunohistochemistry, and as a stabilizing agent for protein reagents. Further applications include, e.g., for serum-free cell culture, as additive for hybridoma cell culture, protein stabilizer, and blocking agent.