Human corneal stroma contains three distinct collagens.

Acetic acid-pepsin extracts of normal human corneal stromas were shown by carboxymethyl cellulose-column chromatography, sodium dodecyl sulfate-slab gel electrophoresis, highly purified collagenase, trypsin sensitivity, and cyanogen bromide peptide mapping to contain types I, III, and IV collagen, with type I by far the predominant species. This degree of collagen heterogeneity in normal human corneal stroma has not been reported previously and may be important in the understanding of wound healing and disease states.