Cultured cells labeled with CMFDA were incubated with ligands immobilized on microplates with various concentrations of EMF10. Cells attached to the plate were lysed by detergent and fluorescence intensity was measured using a microtiter plate reader as previously described.34 CHO cells transfected with αIIbβ3 and with αvβ3 were kindly provided by Dr Mark Ginsberg (Scripps Research Institute, La Jolla, CA). Jurkat cells expressing predominantly α4β1 and K562 cells expressing predominantly α5β1 were purchased from ATCC (Rockville, MD). Recombinant VCAM-1 was a generous gift from Dr Mark Renz (Genentech, San Francisco, CA).