Fine Structural Demonstration of Acid Phosphatase Activity in Auer Bodies

leukocyte physiology related to the genesis or perpetuation of the leukemic state. Ilistochemical,2,’ biochemical4 and fine structural studies5’t’ have defined a number of similarities between Auer rods and the primary dense particles of immature granulocytes, the azurophilic granules. The resemblance of the two types of cytoplasmic organelles has prompted the conclusion that Auer bodies are unusual azurophilic particles, or arise by fusion of azure granules.7.’#{176} One facet of information relating Auer rods to azure granules has been the light microscopic demonstration of the lysosomal enzyme, acid phosphatase, in tile two particle types,”9 suggesting that both are lysosomes.3 However, Freemanit ill a recent discussion of the origin of Auer bodies indicated that: “Since lysosomes are heterogenous, usually electron dense groups of structures with 140 constallt internal structure, it is necessary to utilize histochemical tech-