Magnetic twisting cytometry

Butler JP, Kelly SM (1998) A model for cytoplasmic rheology consistent with magnetic twisting cytometry. Biorheology 35(3) 193-209... 

Recently developed systems attempt to use magnetic particles in the so-called magnetic twisting cytometry (MTC) [62]. The extensive use of magnetic nano/ microparticles in biotechnology is also described in the literature [63]. 

Within a range of acceptable loading rate, the linear elastic approximation can accurately provide a framework for interpretation of data obtained from a variety of biophysical techniques - micropipet aspiration [Kuznetsova, 2007], atomic force microscope (AFM) indentation [Titushkin, 2007], and magnetic twisting cytometry [Vliet, 2003] - developed and refined to measure and characterize the cellular mechanical properties. 

To predict the shape of an adherent tissue cell and quantify the stress distribution inside it, the fibrous actin cytoskeleton or the ECM can be modeled as a two-dimensional network of elastic cables. Previously, elastic cable network provided remarkable quantitative predictions of erythrocyte elastic properties and micropipette aspiration experiments. The cable networks have the additional feature that filaments buckle under compressive load. This model has already been tested successfully to model cell poking, magnetic twisting cytometry, magnetic bead microrheometry experiments. Although the cable network is far from representing the complexity of the actin network mechanics, it incorporates some of its essential features. This model is extended to include the effect of spatial distribution of adhesion points along the periphery of the cell. 

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