Determination of twisting of kinesin molecules during stepping

Kinesin molecules “walk” on microtubules with 8 nm steps. Typically, it is believed to not twist during the motilty. It is this very aspect that we probe using birefringent microspheres of liquid crystalline material RM257 (Merck) upon placing them under crossed polarizers during motility and also using the Optical Micro-Protractor that uses the optical tweezers and detect the twist and the torque generated by the kinesin molecules during stepping.