Technical aspects of buffy coat removal from whole blood and those of platelet production from single buffy coat units.

Technical aspects of buffy coat removal and those of platelet production from the buffy coat were studied using the so-called Amsterdam technique. A long stomach clamp physically separates the buffy coat from erythrocyte concentrate. A better removal of platelets and leukocytes was obtained when blood stored overnight was processed vs. fresh blood. As 71.4 +/- 16.4% of leukocytes was removed from blood stored overnight, it resulted in a mean leukocyte content of 0.84 +/- 0.52 x 10(-9) of the erythrocyte concentrate. The haematocrit of the single buffy coat units have an essential impact on platelet production from buffy coat. A haematocrit of less than 30% seems to be preferable with a volume over 100 ml. The leukocyte contamination of the platelet concentrate is less when it is produced from blood stored overnight.