Monoclonal antibody C1B8A8 recognizes a ventricular secretory product elaborated in the bovine subcommissural organ.

To obtain specific immunological probes for investigation of the cellular and molecular aspects of the subcommissural organ (SCO), we produced monoclonal antibodies directed against extracts from the bovine SCO. An hybridoma cell line (C1A8B8) was isolated by screening the culture media by means of the immunofluorescence method. This clone produces an IgG1 that recognizes the ventricular secretory material of the SCO including Reissner's fiber. A competition test using C1B8A8 immunoglobulin and lectins (concanavalin A and wheat-germ agglutinin) was applied to demonstrate that both the immature and mature forms of the glycoprotein were recognized. This antibody will offer a good tool for immunocytochemical localization and immunoaffinity purification of the antigen and for isolation of cDNA clones encoding it.