Defect in the following is identified by nitroblue tetrazolium test?

Deficiencies of oxidative metabolism (e.g., phagocytosis) are detected with either the nitroblue tetrazolium (NBT) dye test or the dihydrorhodamine (DHR) oxidation test. These tests are based on the ability of products of oxidative metabolism to alter the oxidation states of repoer molecules so that they can be detected microscopically (NBT) or by flow cytometry (DHR). Qualitative studies of superoxide and hydrogen peroxide production may fuher define neutrophil oxidative function. Ref: Gallin J.I. (2012). Chapter 60. Disorders of Granulocytes and Monocytes. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.