Studies of surface GAGs in KKO binding to cell surface. (A) KKO binding to monocytes (diamonds) and to platelets (circles) at increasing concentrations of PF4 as in Figure 1A but with either the vehicle DMSO (open symbols) or in the presence of 10 μM surfen (closed symbols). N = 5 experiments, each done in duplicate. The mean ± 1 SE is shown. (B) Monocytes and platelets pretreated with either chondroitinase ABC alone (■) or heparinase alone (□). Residual KKO binding compared with control (untreated) cells at the optimal PF4 concentration (50 μg/mL) is shown. N = 3 experiments, each done in duplicate. The mean ± 1 SE is shown.