Borate → Biotin

Participants

Reaction Steps

A suspension of XO in 3.2M (NH4)2SO4 (20 mg/ml) (Boehringer Mannheim) was centrifuged at 5000g during 10 minutes and the pellet was dissolved in 1 ml pH 8.5 50 mM, NaCl, 20 mM borate buffer. A solution of biotin X NHS (Biotin ε-aminocaproic acid N hydroxysuccinimide ester, Calbiochem) (1.2 mg/12 12 μl anhydrous dimethylformamide) was added. The solution was agitated by vortexing for two minutes, left at ambient temperature for one hour, and then dialyzed against 0.13M NaCl, 0.07M Na phosphate buffer pH 7.4 (Phosphate buffered saline PBS) containing 0.1% Na azide. The XO-biotin conjugate was then kept at +4° C. under sterile conditions.

Provenance & Evidence