Inhibition of Syk and Src kinases, GPIb, integrin α2β1, or FXIII-mediated fibrin cross-linking, has little or no effect on the time to onset or maximal change in light transmission of the DW. RGDW (150 μM)-treated washed platelets (2 × 10⁸/mL) were incubated for 20 minutes at RT with the following: (A) 100 μM of the Src kinase inhibitor PP2 or 1 μM of the Syk kinase inhibitor VI, or (B) 10 μg/mL of the GPIb-blocking mAb 6D1 or the α2β1-blocking mAb 6F1. Presented tracings are representative of 3 independent experiments. (C) Washed platelets in the absence or presence of RGDW (150 μM) were treated with the FXIII transglutaminase inhibitor T101 at the indicated concentrations 5 minutes prior to adding Thr (0.2 U/mL). Left panel: immunoblot data using a mAb specific for fibrinogen γ-chain of samples solubilized with SDS sample buffer under reducing conditions after 15 minutes of activation. Right panel: corresponding maximal ΔLT of the DW in 3 independent experiments, presented as mean ± SD. WPL, washed platelet lysate.