Basophil and Metamyelocyte
|This image was taken from the March 2001 Cytohematology Proficiency
Test Event - Slide 040. Basophils are granulocytes that contain
purple-blue granules that contain heparin and vasoactive compounds. They
comprise approximately 0.5% of the total leukocyte count. Basophils are
the smallest circulating granulocytes, averaging 10 to 15 Ám in diameter.
The nucleus to cytoplasm ratio is about 1:1, and the nucleus is often
unsegmented or bilobed, rarely with three or four lobes. The chromatin
pattern is coarse and patchy, staining a deep blue to reddish-purple. The
cytoplasm is a homogenous pale blue, but this is often obscured by the
large dark granules. Metamyelocytes have a cell diameter from 10 to 18 µm,
and the nucleus to cytoplasm ratio is 1:1. Indentation of the nucleus
begins at this stage, forming an outline that varies from slightly kidney
shaped, to that of a broad V shape.
Back to Slide 040