myeloperoxidase,
 alkaline phosphatase,
 alpha-naphthyl-acetate-esterase,
 acid phosphatase,
 periodic-acid-shiff (PAS) reaction, and
 Sudan black B stain

These cytochemical reactions have a role in the classification of acute leukemias and, as a rule, occur in parallel with cytomorphologic classification.

Cytochemical reactions either confirm cytomorphologic classification or suggest another cytomorphologic classification and serve as a subsidiary diagnostic method in it, first of all in the differentiation of AML from ALL.