Glossary

Erythrocyte

An erythrocyte is a red blood cell. Erythrocytes are the densest major component of blood and settle to the bottom of the tube first under centrifugation. In PRP preparation they are what you are trying not to draw.

Figure

The red cell layer

PLASMA about 55% of the column BUFFY COAT platelets and leukocytes. about 1%. Drawn to scale. This is the whole target. RED CELLS densest fraction. sediments first. CENTRIFUGAL FORCE

Figure. The densest fraction, and the one that sediments first. In a PRP draw it is what you are trying not to pull, which is materially harder when the layers have separated on a slant.

In practice

Red cell contamination in a PRP draw is the most common technique fault, and it is more likely with a fixed-angle rotor because the layers separate on a slant.

See also