Sanne de Bruin

188 Chapter 7 The percentage of CD62P activationmet blood bank standard. All samples showedmax- imal response to thrombin receptor-activating peptide (Figure 5). Similar results were observed in apheresis derived PCs and in PAS-E stored PCs (supplement, table S1). All blood products were culture negative before and after biotinylation Figure 4. Annexin V expression of a fresh PC (day 1, left panel, n=6) and a stored PC (day 7, right panel, n=6). On day 1, the bioPLT did not show a statistically significant difference in Annexin V positive cells, as compared to control: 1.2% (0.9%-1.7%), p=0.56 and sham: 3.4% (1.6%-5.5%), p=0.16. At day 7, the bioPLT also showed no significant difference in annexin V positive cells: bioPLT: 10.1% (8.2%-15.8%) compared with the control: 9.9%(7.3%-15.6%), p=0.09 and the sham 9.6%(7.9%-16.0%), p=0.16. The effect of storage on platelet quality parameters Platelet quality parameters were measured directly after biotinylation of a 50 mL ali- quot of fresh (day 1) and stored (day 7) buffy-coat derived PCs. Both fresh and stored platelets fulfilled platelet quality standards after biotinylation (Table 1). Platelets that were biotinylated at day one of storage were subsequently stored for three more days and tested for stability of the biotin-label and platelet quality parameters. Storage of