Attachment of Plasma Membranes of Cultured Cells to Silicon Chips for High Magnification Imaging in Scanning Electron Microscopy

In the membrane preparation method described in this paper, a polylysine-coated silicon chip is adsorbed to the exposed apical surface of a cell monolayer. Upon removal, the adsorbed chip separates the plasmalemma from the residual bodies of the cultured cells. This sandwich-membrane separation approach simplifies access to the cytoplasmic aspects of both the apical and the basal plasmalemma which remains on the culture substrate and is covered to a varied extent by cytoplasmic infrastructures. To stabilize the attached membranes, small crosslinking agents are used in a controlled osmium impregnation. Large crosslinkers are avoided since they induce thickening of fine structures. Optimal conditions for attachment of plasmalemma of cultured adrenal endothelial cells to the cationic chip are defined. Effective cleaning procedures of the chips and useful molecular weights of polylysine are determined by quantitating colloidal gold adherence to the surface of the chips. The specimens are examined by high resolution scanning electron microscopy