Sialic acid masked membrane antigens of clonal functional glial cells

Antisera have been prepared to clonal cultured rat astrocytic cells (C6 cells) and clonal human astrocytic cells (CHB4 cells). When cultured glial cells are grown in the presence of neuraminidase the serological activity of the cell membrane with homologous antiserum is increased extensively. A similar activation of serological activity can be effected by incubating washed harvested cells with this enzyme. Membrane bound N‐acetyl‐neuraminic acid is extensively reduced by either incubation. The activity responsible for promoting the enhanced serological activity co‐chromatographs and co‐electrophoreses with neuraminidase. Proteolytic digestion, unlike neuraminidase treatment, was unable to enhance the serological activity of cultured glial cells.