The Composition of the Buffy Coat in a Centrifuged Blood Sample

Question:

What is the buffy coat of the middle layer of a centrifuged blood sample composed of?

Answer:

The buffy coat of the middle layer of a centrifuged blood sample is composed of white blood cells (leukocytes) and platelets (thrombocytes).

When a blood sample is centrifuged, it separates into three distinct layers: the top layer is plasma, the middle layer is the buffy coat, and the bottom layer is red blood cells (erythrocytes). The buffy coat is a thin, whitish layer that sits between the red blood cells at the bottom and the plasma at the top.

The buffy coat is so named because it appears buff-colored when viewed with the eye. Under a microscope, it is possible to see the individual white blood cells and platelets within the buffy coat layer. White blood cells play an important role in the immune system, and platelets are necessary for blood clotting.