Through the Microscope: Blood Cells - Life's Blood

Myeloblast

The myeloblast is the first stage of the granulocytic series that is identifiable by light microscopy. It may be dificult to distinguish myeloblasts from other blasts in the peripheral blood unless one uses special stains or infers their identity from the presence of other immature cells of the same line.

A myeloblast can be distinguished from a promyelocyte by its lack of cytoplamic granulation. The nucleus is composed of very fine nonaggregated chromatin that stains light blue to reddish-purple with Wright's stain. Two to five distinct nucleoli are usually present. The nucleus is often bordered at one side by a distinct perinuclear zone.