Pages 547-557, Language: EnglishGonshor, AronAutologous platelet-rich plasma is a source of platelet-derived growth factor (PDGF) and transforming growth factor beta (TGF-ß), both important in accelerating hard and soft tissue maturation. This article describes a two-step centrifugation method to sequester and concentrate platelets to a level four to eight times baseline whole blood values. The technique produces concentrations of PDGFAB above 500% and TGF-ß1 greater than 800%. Flow cytometry measuring pselectin expression shows that the platelets remain quiescent throughout the procedure, maintaining their integrity and viability, with no inadvertent activation.