nitroblue tetrazolium test


ni·tro·blue tet·ra·zo·li·um test (NBT test),

a test to detect the phagocytic ability of polymorphonuclear leukocytes by measuring the capacity of the oxygen-dependent leukocytic bactericidal system.

NBT test

Nitroblue tetrazolium test. A quantitative test of neutrophil peroxidase activity. The test measures phagocytic capacity and the ability to reduce NBT, which precipitates as blue-black clumps of reduced NBT (formazan), if superoxide or O2– is produced in test cell, indicating an intact hexose monophosphate shunt. NBT reduction is defective in chronic granulomatous disease.

nitroblue tetrazolium test

(nī′trō-blū) A test of the ability of leukocytes to reduce nitroblue tetrazolium from a colorless state to a deep blue. It is used as a marker of nitric oxide synthase. The reduction of NBT may be used in the rapid diagnosis of urinary tract infections and in the study and diagnosis of chronic granulomatous disease and other illnesses in which there are defects in the oxidative metabolism of phagocytic white blood cells.