Mechanical manipulation of animal cells: cell indentation

Determining the mechanical properties and behavior of cells has been studie d through a variety of methods including micropipette aspiration, atomic fo rce microscopy (AFM), magnetometry, rheology, and cell indentation. Using t he cell poker technique, the force required to indent the cell surface by a glass stylus or the relaxation time of the cell membrane can be determined . This method provides information about both the mechanical properties of adherent cells and the internal cytoskeleton. For example, using the cell p oking technique showed that F9 mouse embryonic carcinoma cells were similar to 20% more resistant to indentation by the cell poker compared to F9 vinc ulin-deficient (5.51) cells, which were derived by chemical mutagenization of F9 cells. This was confirmed in viscoelastic measurements using AFM, mag netometry, and rheology.