Platelets are small fragments, but they are of crucial importance for the coagulation. The risk of spontaneous bleeding increases when the level of platelets falls below a thrombocyte particle concentration threshold value of 50 x 109/L. In those cases a platelet transfusion might be compulsory. Ongoing research tries to improve the quality of the platelets and to increase the safety of the method used. However, we still need to better understand which factors that affect how patients react upon platelet transfusion.

Platelet transfusions can be necessary during treatment of patients with thrombocytopenia or impaired platelet function. Platelet function in platelet concentrates (PC) deteriorate with storage time. Studying swirling is often used to control the quality of PC?s before transfusion but the method has some disadvantages. Therefore other methods can be useful, for example impedance aggregometry (IA, Multiplate® Analyzer) to measure platelet function.     In this study the change in platelet function over time was examined in buffy coat and Apheresis platelets with IA where aggregation had been induced with adenosine diphosphate (ADP) and collagen.