Circulating platelets differ with respect to size, density and functional ability.
In several experimental settings it is of vital importance that a representative platelet-rich
plasma (PRP) is extracted from the anticoagulated blood. We therefore investigated
the effect of centrifugation time and gravitational force on platelet yield and platelet
volume distribution in PRP obtained by a single step slow centrifugation.
Methods. From each of 12 healthy male blood donors, 357 ml of venous blood were mixed
with 63 ml citrate phosphate dextrose in a plastic bag. 20 ml aliquots of the anticoagulated
blood were transferred into 30 ml screwcap polycarbonate tubes (Nalgene Labware).
PRP was prepared by a single step slow centrifugation in a microprocessor-controlled
bench centrifuge (Hettich Rotanta/RP). The gravitational force was calculated at the
bottom of the tube. Centrifugations were performed at 180, 200, 220, 240, 260 g for
10 min, at 180, 200, 220, 240, 260 g for 15 min and at 120, 140, 160, 180, 200 g for
20 min. Three hours after blood collection, the platelet count, mean platelet volume
(MPV) and platelet distribution width were determined in PRP and anticoagulated blood
with an impedance cell counter (Coulter Counter Model S-Plus VI). Student's t-test
was employed for comparison of mean values.
Comments. Very precise centrifugation conditions can be provided by using a microprocessor-controlled
centrifuge and a "fully representative" platelet population can be isolated with a
single step slow centrifugation method.
