In brief, the reaction mixture consisted of 2.70 ml of 40 mmol/l
sodium carbonate buffer containing 0.1 mmol/l ethylenediaminetetraacetic
acid (EDTA) (pH 10.0), 60 ml of 10 mmol/l
xanthine in 25 mmol/l sodium hydroxide solution, 30 ml of 5 mg/ml
bovine serum albumin (BSA), 30 ml of 2.5 mmol/l nitroblue tetrazolium
(NBT) and 60 ml of extracts.