Activated LFA-1d/d splenic T cells were plated on immobilized ICAM-1-Fc (µg/ml) in the presence of 6 mM Mg2+. A Phase image was taken every 10 s. 1 s of film equals 1 min real time. Images were taken with a 40X lens and AQM2001 Kinetic Acquisition Manager software (Kinetic Imaging Ltd.).