In a centrifuged blood sample, roughly what fraction of the total volume does the buffy coat normally occupy?

1. The buffy coat holds only the leukocytes and the platelets. 2. Both are vastly outnumbered by erythrocytes, which alone account for roughly 45 percent of a sample. 3. The layer they form therefore normally constitutes less than 1 percent of the sample. 4. About 45 percent is the erythrocyte fraction and about 7 percent is the plasma protein fraction, so neither describes the buffy coat. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 18 "The Cardiovascular System: Blood", section 18.1 An Overview of Blood_