Müller cells, the specialized radial glia found in vertebrate retinas, were enzymatically dissociated from adult cat retinas and grown in culture. The cells were processed for immunofluorescence microscopy at times ranging from 4 hr to 3 months in culture. Labeling with antibodies specific to glial fibrillary acidic protein, cellular retinaldehyde binding protein, glutamine synthetase, carbonic anhydrase C and alpha crystallin, all proteins known to be found in Müller cells, was detected in the cultured cells. Immunoblot analysis of the cultured cells showed single protein bands corresponding to the appropriate molecular weights of the antigens.