Scanning electron microscopy of Heinz bodies in feline erythrocytes.

Whole blood and partially lysed blood films from 5 cats having 20 to 91% of the erythrocytes containing Heinz bodies were examined, using the light microscope and the scanning electron microscope. Heinz bodies were detected in the intact erythrocytes from 3 of the cats as abruptly elevated and distinctly demarcated protuberances in various shapes, sizes, and locations. The Heinz bodies were located just beneath the cell membrane either centrally or near the cell margin and varied in their projectional magnitude. Brilliant cresyl blue staining of blood of these 3 cats revealed prominent Heinz bodies within, and projecting from, the erythrocytes. In contrast, Heinz bodies were not identified on scanning electron microscopy of intact erythrocytes of the remaining 2 cats even though Heinz bodies were found on their blood films stained with brilliant cresyl blue. Scanning electron microscopy of partially lysed blood smears of all 5 cats revealed Heinz bodies of various sizes in the erythrocyte ghosts. Furthermore, blood smears from the 3 cats having distinct Heinz bodies in intact erythrocytes revealed small dense intracellular granules distributed singly or coalesced in small clumps. Further aggregation of these clumps was assumed to result in the formation of a single large Heinz body. The 3-dimensional nature of Heinz bodies was clearly apparent in lysed blood smears.