<prompt> Nitro-blue tetrazolium test is done for?Chronic glomerulonephritisChronic granulomatous disorderAcute granulomatous diseaseChediak Higashi syndrome  <response>: Ans. b Chronic Granulomatous disorderRef: Robbins pathology 9th ed. 237-238Nitro blue tetrazolium is used in a diagnostic test, particularly for chronic granulomatous disease. When there is an NADPH oxidase defect, the phagocyte is unable to make reactive oxygen species or radicals required for bacterial killing. As a result, bacteria may thrive within the phagocyte. The higher the blue score, the better the cell is at producing reactive oxygen species. 