Fig. 5. Rupture force plotted against the natural logarithm of loading rate for E-, P- and L-selectin binding to PMNs. Data comprise at least eight independent experiments and a range of reproach velocities for each selectin, conducted on separate days to validate reproducibility. Each force spectrum represents at least 2000 successful events. The superimposed solid lines indicate the non-linear least-squares fit over the entire range of experimental loading rates, found from the probability density function for bond rupture and corresponding Bell model parameters.