Previous studies of fibronectin (FN) distribution in eye tissue have relied on immunofluorescence (IF) techniques on frozen sections, and have not included the rat. Using rat eyes, a technique was developed for immunoperoxidase (IP) staining of formalin fixed paraffin embedded material, and the results were compared to those obtained by IF. IP was technically more difficult, and required pepsinization of tissue after formalin fixation to obtain consistent results. The optimum pepsin time varied for different structures in the eye. IP offers better tissue preservation and stain resolution. Results with IF were consistent with those observed with the newly applied IP. The distribution of FN in rat eyes was similar though not identical to that reported in other species. Prominent stain was observed in the conjunctiva, basement membrane of the corneal epithelium, corneal stroma, anterior aspect of Descemet's membrane, trabecular meshwork, perivascular stroma of the ciliary body, choroid and retinal blood vessels. Lens structures, vitreous, and internal limiting membrane of the retina were negative.

• EY01634/EY/NEI NIH HHS/United States