Fig. 2. Detection of HUVEC surface A2 and p11 by biotinylation. Following treatment with thrombin or TRAP, HUVECs were biotinylated using membrane-impermeable sulfo-NHS-biotin. Surface-labeled proteins were affinity depleted using avidin-Sepharose and probed by western blotting using anti-A2 mAb, while p11 was immuno-depleted and detected using HRP-avidin.