Using a light touch to measure protein bonds

The strength of actin binding protein interactions cross-linking a surface bound and bead tethered actin filament are probed using force from an optical trap. Filamin in green which forms networks of actin filaments shown as a confocal image on the right and alpha-actinin in blue which bundles actin filaments, shown as an image on the left, were probed using this assay configuration. Image courtesy / Hyungsuk Lee, Jorge M. Ferrer, and Matthew J. Lang