METHOD FOR DETERMINATION OF SUPEROXIDE DISMUTASE ACTIVITY Russian patent published in 2006 - IPC C12Q1/26 G01N33/50 

FIELD: biochemistry, in particular method for determination of antioxidant enzyme superoxide dismutase (SOD) activity.

SUBSTANCE: claimed method includes preliminary determination of appropriate xanthine oxidase activity (E₃) in examined sample, namely examined sample is added into dish to incubation medium containing 50 mM sodium carbonate solution; 0.1 mM EDTA solution; 37.5 muM nitroblue tetrasolium (NBT) solution in 50 mM phosphate buffer (pH 10.2); and 73 mul of 0.1 mM xanthine solution in 0.5 N NaOH and free from xanthine oxidase. Optical density variation is registered for 3-5 min at 560 nm wavelength using obtained kinetic curve. (E₃). Initial velocity of NBT reduction without SOD is determined according to known method. In the same dish examined sample is added, wherein said sample contains SOD in amount sufficient to change solution optical density caused by NBT reduction at rate of 0.015-0.02 U/min and selected for one-type samples under conditions wherein said variations are occurred at substrate excess reduction in proportional variations of reaction velocity. Optical density variation per one minute in terms of protein amount in sample is calculated and protein amount in examined sample is determined. SOD activity is calculated according to specific formula.

EFFECT: method of increased accuracy and reliability.