Optical tweezers across scales in cell biology

Optical tweezers (OT) provide a noninvasive approach for delivering minute physical forces to targeted objects. Controlling such forces in living cells or in vitro preparations allows for the measurement and manipulation of numerous processes relevant to the form and function of cells. As such, OT have made important contributions to our understanding of the structures of proteins and nucleic acids, the interactions that occur between microscopic structures within cells, the choreography of complex processes such as mitosis, and the ways in which cells interact with each other. In this review, we highlight recent contributions made to the field of cell biology using OT and provide basic descriptions of the physics, the methods, and the equipment that made these studies possible. Optical tweezers (OT) can measure or apply minute forces inside cells noninvasively.Recent developments in OT technology have allowed insights into the structure, function, and behavior of cells.Particular progress has been made in understanding mitotic machinery, cellular viscoelasticity, and metastasis.Emerging methods in optical physics promise to extend the breadth and utility of OT in the years to come.