Leukocyte-poor platelet concentrates from buffy coats. The Dutch experience

Following centrifugation the whole blood is manually separated into plasma, buffy coat and red cells in a plasma extractor or automatically processed in a special device designed for this method of blood separation. To obtain cell-free plasma it is important to terminate plasma expression when a layer of approximately 2 cm of plasma remains over the cells; a clamp or another device dividing the bag into two compartments should then be applied approximately 2 cm under the demarcation between plasma and buffy coat/red cells to prevent leukocytes falling back into the red cell layer. The buffy coat is expressed by rolling up the bag over the clamp or by a flat press in the automatic device. (DBO)