White blood cells from peripheral blood and bone marrow have been sectioned for study in the electron microscope. Methods of fixation and handling are described. Most of the usual blood cell types have been tentatively identified, and their fine structure is described. The high resolving power of the electron microscope promises to reveal details previously unsuspected, as well as to extend and clarify existing knowledge concerning the cytology of blood cells, both normal and pathologic.
Ultra-thin sectioning, while still a very difficult art, appears to be the best method currently available for visualizing the fine structure of white blood cells, which would otherwise be too thick for penetration by the electron beam. Conditions of satisfactory fixation and dehydration are extremely critical, and care must be exercised in the interpretation of all results in order to separate gross fixation artifacts from the finer precipitation of protoplasmic material which may approximate a true picture of the living cell.