Application of freeze‐etch replication for the observation of the cell‐extracellular matrix interface of cultured cells

SUMMARY In order to investigate the ultrastructural three‐dimensional relationship between extracellular matrices (ECM) and the plasma membranes of cultured cells, a freeze‐etch replica method was devised. Bovine corneal endothelial cells were cultured on a Collodion film which covered a hole punched in a plastic coverslip, and were quickly frozen with a slammer with their basal surface facing a liquid nitrogen‐cooled copper block. The cells were placed upside‐down in a Balzers freeze‐fracture machine and freeze‐etched, and then platinum‐carbon replicas were obtained. The structure of the ECM‐plasma membrane interface was observed successfully and so this technique provides a new approach for investigating the ECM‐plasma membrane (matrix‐receptor) relationship.