Movie 1.

The reversibility of integrin αLβ2 activation. The movie shows the micropipette adhesion frequency assay. The RBC (left) bearing E-selectin-Ig (6 μm^-2) and ICAM-1-Ig (9 μm^-2) was repeatedly brought into contact with the neutrophil. The contact time was alternated between 2 and 15 s. The first 80 adhesion contact cycles are shown. The approach and contact phases were speeded up 4x to save time but the retraction phase was in real time to allow observation of the adhesion events. The numbers shown on the bottom left corner are real time.