Demonstration of immunoglobulin on the surface of thymus lymphocytes.

Immunoglobulin molecules on the surface of mouse thymus cells have been shown by immunofluorescence. Ninety-five to 100 per cent of thymus lymphocytes were found to bind polyvalent rabbit anti-mouse immunoglobulin, although the density of the fluorescence was much less than that on the surface of B lymphocytes derived from the spleen. Two purified antisera, an anti-IgM and an anti-kappa chain serum, also stained the cells. The resynthesis of these immunoglobulin molecules was demonstrated after they had been removed with pronase.