Drug buffer	Final concentration	Amount
Ascorbic acid	0.3 mg/mL	15 mg
BSA	3 mg/mL	150 mg
KOH (1 M)	n/a	To pH 7.4
Assay buffer	n/a	To volume
Total	n/a	50 mL

Sterile filter and store at 22°C for up to 24 hours