The cytoskeleton is a network of crosslinked, semiflexible filaments, and it has been suggested that it has properties of a glassy state. Here we employ optical-trap-based microrheology to apply forces to a model cytoskeleton and measure the high-bandwidth response at an anterior point. Simulating the highly nonlinear and anisotropic stress-strain propagation assuming affinity, we found that theoretical predictions for the quasistatic response of semiflexible polymers are only realized at high frequencies inaccessible to conventional rheometers. We give a theoretical basis for determining the frequency when both affinity and quasistaticity are valid, and we discuss with experimental evidence that the relaxations at lower frequencies can be characterized by the experimentally obtained nonaffinity parameter.

The mechanics of cells or cytoskeletons have been understood either as a network of semi-flexible polymers or a glass. Here we employ optical-trap based microrheology to apply forces to cytoskeleton and measure the highbandwidth response at an anterior point. Simulating the highly nonlinear and anisotropic stress-strain propagation assuming affinity, we found that theoretical predictions for the quasi-static response are only realized at high frequencies inaccessible to conventional rheometers. We give a theoretical basis for determining the critical frequency when both affinity and quasistaticity are valid, and discuss with experimental evidence that the relaxations at lower frequencies can be characterized by the experimentally obtained non-affinity parameter.

detecting con formational change, ligand desorption and current at thc same time and it is preferable to fix ion channel to solid support in the [ipid bilayer. We have previous]y reported that the reeonstitution of ion channet fixed onto the solid support such as agarose bead and the tip of AFM cantilever into lipid bilayer. In this study, we conducted reconstitution of ion channet into Iipid bilayer using g)ass needle as a solid support. The tip ofglass needle (

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