Crystallin expression in human lens epithelial cells in culture and a number of non-lenticular tissues was studied by the technique of immunoblotting using monoclonal antibodies. The expression of alpha A, beta 5 and beta 6 crystallins per unit number of cells increased with passage number while alpha B appeared to be constant Lentoid bodies derived from cultured human lens epithelial cells not only expressed gamma-crystallin and MP26 as previously demonstrated, but also produced alpha A, alpha B, beta 5 and beta 6 crystallins. In human non-lenticular tissues including ciliary body, vitreous body, neural retina, cultured retinal pigment epithelial cells and scleral fibroblasts, alpha B-crystallin was detected, but was undetectable in cornea and iris. Alpha A was present only in the lens. These studies demonstrate that HLE cells maintain the ability to synthesize crystallins through several passages. Following differentiation, they not only synthesize gamma-crystallin and MP26 but continue to express alpha- and beta-crystallins similar to differentiated lens fiber cells in vivo. Consistent with previous observations, the expression of alpha B-crystallin does not appear to be specific for the lens.