Protocol to quantify mechanical properties of cells using optical tweezers

Mechanical properties of cells determine their ability to deform when subjected to force, which is crucial in many biological processes. Here, we present a protocol to quantify these properties on living cells by applying piconewton-range forces with optically trapped microspheres. We describe steps for sample preparation of both adherent and suspended cells, calibration of optical trap stiffness, and generation of force-deformation curves. We next detail how to quantify cellular mechanical properties from the resulting data. For complete details on the use and execution of this protocol, please refer to Rodenburg et al. 1 • Steps to measure cell mechanics with optical tweezers • Guidance for sample preparation and instrument setup • Instructions for quantification and analysis of mechanical properties Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. Mechanical properties of cells determine their ability to deform when subjected to force, which is crucial in many biological processes. Here, we present a protocol to quantify these properties on living cells by applying piconewton-range forces with optically trapped microspheres. We describe steps for sample preparation of both adherent and suspended cells, calibration of optical trap stiffness, and generation of force-deformation curves. We next detail how to quantify cellular mechanical properties from the resulting data.