Figure 5

Comparison of HB3 platelet-mediated clumping frequencies using fresh versus stored platelets. Platelet-rich plasma (PRP) samples from fresh versus 4°C-stored blood from the same donors were compared for their ability to mediate clumping of HB3 parasites. For donors 1 and 2, stored PRP was obtained from 7 day-old whole blood samples and compared on the same day to PRP from fresh blood from the same donors. For donors 3 and 4, stored PRP was obtained from 10 day-old whole blood samples and compared on the same day to PRP from fresh blood from the same donors. In all cases the fresh PRP was kept at room temperature and used within five hours of venepuncture. In vitro platelet-mediated clumping reactions were performed at 10% Ht and 1% Pt. The clumping frequency is expressed as the percentage of IE in clumps out of at least 500 IE counted. Clumping frequency values in the graphs are the mean and standard deviation of three wet preparations counted from each time point.