Scanning one of the beads confined in optical tweezers pulls the actin past the myosin motor protein, which preferentially binds at sites separated by the 36 nm helical repeat distance of actin.
Reprinted by permission from Macmillan Publishers Ltd: Veigel et al., Nature Cell Biol. 4, 59–65, copyright 2001.
Fig. 13.1 — Single molecule assay using a dual optical tweezers