Appearance (Colour)
Pale blue- gray
Appearance (Form)
Powder
Activity
min. 3000 units/mg powder
Unit Definition
One unit will inhibit the rate of reduction of cytochrome c by 50% in a coupled system, using xanthine and xanthine oxidase, at pH 7.8 at 25 °C in a 3.0 mL reaction volume. The xanthine oxidase concentration should produce an initial (uninhibited) ΔA550 of 0.025 ± 0.005 per minute.
Enzyme solution for activity determination
Prepared in potassium phosphate buffer, pH 7.5.
