To study the specific properties of lens cells with particular reference to congenital cataracts, tissue culture methods are being developed. The cell culture of lens epithelium has progressed so that cloned cell lines from mouse lens were obtained. Certain differentiated characteristics of lens cells have been maintained by the cultured epithelial cells. Gamma crystallin, normally associated with the differentiated fiber cells, has been demonstrated using slab gel electrophoresis and immunodiffusion. In addition, proteins synthesized by lens epithelial cells in culture have been studied using autoradiographic methods. 125I radioimmunoassays for alpha, beta, and gamma crystallin have been developed to check for these lens-specific proteins. Studies of cells cultured from normal mouse lens and mouse lens from a strain with hereditary cataracts have been performed with scanning and transmission electron microscopy and histochemistry.