Gross and Microscopic Evaluation of the Buffy Coat

Gross and microscopic evaluation of the buffy coat can be an extremely valuable procedure and is often overlooked. While microscopic evaluation of a buffy coat preparation is not a test that should be done on every whole blood sample obtained – unlike packed cell volume (PCV), total protein (TP), and blood film evaluation – when used appropriately, it can provide valuable diagnostic data. On the other hand, gross evaluation of the buffy coat on every microhematocrit tube prepared for PCV and plasma TP determination should always be done. This chapter will provide a protocol for making buffy coat preparations and an explanation of the indications for and value of reviewing a stained buffy coat slide.