Figure 7. Bead displacements for CHO.B2 cells migrating on FN or LN.

Cells were plated onto bead embedded polyacrylamide substrates (E = 1 kPa) coated with adhesive ligand. The relative bead displacements were measured in regions of protrusion, retraction and the cell body. Maximum deformation was measured in gel sub-regions (see Methods) by interpolating bead displacements onto a regular grid during events of protrusion and retraction. Independent protrusion and retraction events show no significant difference (P = 0.61 and P = 0.18, for FN and LN respectively, in a cell paired t-test), indicating that in each case we measured the maximum deformation of the gel. Cells plated on FN-coated gels deform them significantly more than LN-coated gels (P = 0.028 and P = 0.016 for protrusion and retractions respectively), suggesting that they exert stronger forces. Data are expressed as the mean ± SEM (n = 13 cells).