The NBT reduction assay is used to:
|A||evaluate granulocyte function|
|B||evaluate T cell function|
|C||determine whether PMN’s can produce superoxide|
|D||stain B cells|
Phagocytes produce superoxide free radicals by NADPH oxidase to kill phagocytosed organisms.
These radicals directly reduce nitroblue tetrazolium into an insoluble formazan.
Hence it is positive in normal individuals. In chronic granulomatous disease these radicals are not produced. Hence the NBT test is negative.