If you centrifuge (spin) whole blood you will find the band of white blood cells and platelets (the Buffy coat) is much thinner than the packed red blood cells below it. This difference reflects the fact that ________. If you centrifuge (spin) whole blood you will find the band of white blood cells and platelets (the Buffy coat) is much thinner than the packed red blood cells below it. This difference reflects the fact that ________.