An improved method for the isolation of cells from tissues: prevention of cell rounding enhances spreading and locomotion of keratinocytes (epitheliocytes).

Benzamide (10mM) in Ca-free solution anesthetizes small cold blooded animals such as tadpoles of Rana temporaria, Xenopus laevis and an aquarium fish, guppy (Lebistes [Poecilia] reticulatus). Trypsinization of tails of tadpoles in Ca-free, benzamide-supplemented solution permits isolation of keratinocytes (epitheliocytes) maintaining polygonal shapes and prevents cell rounding. Such cells quickly attach to glass, spread and commence locomotion in contrast to those cells which assume spherical shape after standard trypsinization.