Light microscopic, immunohistochemical localization of the pia-glial basal lamina

The current histologic methods for studying the pia-glial basal lamina (BL) are inappropriate for high contrast, permanent light microscopy preparation. We have developed a staining technique for epithelial BL which is highly specific, extremely sensitive, permanent, relatively inexpensive, and suitable for light or electron microscopy (EM). Central nervous system (CNS) basement membrane zone (BMZ) antigens were isolated by the technique of Meezan (1975) from female albino Wistar rats. Using this CNS BMZ preparation as an antigenic source, a hyperimmune rabbit serum was developed. This serum was exhaustively adsorbed with rat splenic pulp to remove undesirable antibodies to endothelial BL and collagen. The peroxidase-antiperoxidase indirect antibody technique was used to test the staining specificity of this splenic adsorbed serum on different tissues containing BLs of known origin and/or function. The results indicated that this BL staining technique was specific for epithelial BL of the rat and of some other species.