BSA Alkyne is commonly used for the positive control of the Click chemistry-based enrichment of alkyne-tagged proteins. Bovine Serum Albumin (BSA) is chemically modified on a single cysteine residue with N-Propargylmaleimide (MV 130.12). It is provided as lyophilized solid. To prepare a working 1 mg/ml solution, resuspend lyophilized BSA-conjugate in 500 µl of 0.5 x PBS pH 7.4. Do NOT add sodium azide.