Comparison of osmium/sonication and EDTA/sonication microdissection techniques in exposing the adepithelial basal...

We have used two epithelial-stripping techniques in our studies of the basal lamina in the developing rat colon. The first involves prolonged osmication followed by sonication; the second uses chelation of calcium by EDTA followed by sonication. Both techniques remove the epithelium from the basal lamina; however, the EDTA/sonication technique appears to produce a cleaner adepithelial surface of the basal lamina. In addition, the fine structure of the basal lamina appears to be better preserved in specimens prepared by the EDTA/sonication technique. In contrast, the basal lamina of specimens prepared by the osmium/sonication technique had a shattered appearance that we believe is due to an increase in the fragility of the delicate fetal basal lamina.