Anita Choudhury, Manoj Kumar Patro, Dinabandhu Bishoi, Debi Prasad Mishra

BACKGROUND Myeloperoxidase (MPO) staining is a cytochemical stain was the first step in morphological characterization of two basic types of Acute leukemia.1,2 Until recently when the procedure was eliminated from the diagnostic protocol because of the proven carcinogenic potentiality of Benzidine. In advanced laboratories the procedure is now replaced by immunocytochemical demonstration of MPO. The main disadvantage of immunocytochemical stain is cost associated with the procedure, hence it is not possible for use in developing and under-developed countries. Besides the carcinogenic threat, the routine MPO staining procedure is also time consuming. The present study was aimed at, evaluating the new method that, successfully removes the use of the benzidine by DAB which has uncertain carcinogenic potentiality. MATERIALS AND METHODS 130 blood smears both peripheral blood smears and bone marrow aspirate smears were stained by the routine benzidine method and new DAB method and evaluated for stain intensity, cell morphology and background by two pathologists and each parameter was graded from 1 to 3. The total score for each case was calculated and compared using statistical formulae. RESULTS The new test has the additional advantage of being simple and less time consuming with excellent staining properties. CONCLUSION The newer technique using DAB was found to be a better procedure with good staining qualities, easy to perform as the liquid solution is stable and it is not an established carcinogen