The surge technique: a method to increase purity of platelet concentrates obtained by centrifugal apheresis

A surge technique has been developed to increase the purity of high-yield platelet concentrations prepared on a blood processor with the Latham bowl. The surge technique combines elutriation with centrifugal separation, utilizing plasma recirculated from the plasma/air bag back into the centrifuge bowl to elute platelets from the red cell mass. Platelet concentrates prepared by surge collection with six separation cycles (n = 22), contained an average of 3.9 +/- 1.4 X 10(11) platelets, with 0.15 +/- 0.11 X 10(9) leukocytes, and red cells below the level of detection. The surge technique reduces collection time by 4 minutes per cycle and eliminates the need for a secondary centrifugation; thus, 96 minutes donor processing time would permit eight separation cycles. Platelets collected by the surge technique exhibited unaltered morphology and capacity to take up radioactively labeled serotonin in vitro compared to pre-apheresis controls. Results from in vitro functional studies also indicate that the capacity of platelets collected with the surge technique to respond to various concentrations of adenosine diphosphate, collagen, and thrombin by aggregation and secretion of both serotonin (dense bodies) and beta-thromboglobulin (alpha-granules) was not significantly different (p less than or equal to 0.05) from that of pre-apheresis controls.