The fine structure of rabbit platelets fixed in acetaldehyde

Abstract
The morphology of platelets fixed in acetaldehyde and postfixed in osmium tetroxide was compared with that of platelets fixed in glutaraldehyde followed by osmium tetroxide. Many platelets became rounded after acetaldhyde fixation. Membranes, granules and mitochondria were well preserved and cytoplasmic microfilaments became apparent. Very dense granules were obvious after acetaldehyde fixation alone and after acetaldehyde/glutaraldehyde/osmium tetroxide triple fixation, but not after acetaldehyde/osmium tetroxide double fixation. Microtubules were never seen. Intracytoplasmic vacuoles assumed exaggerated prominence. The authors relate the alterations in the vacuolar system and changes in platelet shape to a loss of cytoplasmic microtubules. They suggest that the changes are induced, in part by the low temperature of fixation, and in part by the weak fixative action of the aldehyde.