A novel procedure for reversing cell monolayers is described. Cells are embedded in liquid gelatin containing ethylenediaminetetraacetic acid, cooled down to solidify gelatin, and then reversed. The main advantage of this technique is that cells are fixed after reversing so that the extracellular matrix does not obscure the cell surface. No substantial migration of receptors is likely to have taken place judging from the concentration of fibronectin receptor in typical focal or extracellular matrix contacts.