Glycogen and DNA content of corneal epithelium: comparison of preparation methods.

Three methods of corneal epithelial preparation for subsequent analysis of epithelial glycogen and DNA content were compared: scraping, lamellar stripping, and in situ freezing. All three methods gave good recovery of these substances. However, there was incomplete recovery of the sample using the in situ freezing method and significant contamination of epithelial samples by stroma in the lamellar stripping method. Thus, scraping is the most reliable method of collecting pure epithelial samples for glycogen or DNA analysis.