A simple model for the study of effects of the extracellular matrix on the cell morphology in vitro

In the present work, a simple technique is proposed to study the effects of native extracellular matrix (ECM) of one cell type on the properties of other cell types. It is based on a procedure in which, after cells of one type are removed from the substrate, cells of another type are seeded on the same substrate. To obtain preparations of native ECM, cells were removed from the substrate by 0.02% EDTA only, without any proteolytic enzymes. Cells were placed on coverslips in standard Petri dishes and incubated in a culture medium for a time sufficient for adhesion and spreading, but not long enough to undergo mitosis. Up to four coverslips per Petri dish can be incubated, and various combinations of ECM and cell types can be used in one dish. It is important, therefore, that the different "ECM-cell" combinations are present in the same culture medium. For evaluation of ECM effects, the area occupied by the cell on a substrate and the perimeter of the cell were measured, and frequencies of cell distribution were calculated according to these parameters.