Ultrastructure of platelets in PRP from patient 1 as shown by standard transmission electron microscopy. Note the presence of platelet agglutinates and platelets of different size and shape that include round forms. Granules are randomly distributed and the platelets show no signs of activation (A). Platelets are often attached through discrete areas of surface contact; arrows highlight how protein bridges can be seen clearly at some interfaces (B), while at other interfaces the membrane surfaces appear to be in direct contact (C). Scale bar in panel A equals 0.5 μm; scale bars in panels B and C equal 200 nm.