Demonstration by affinity chromatography of the cell-free synthesis of ribonuclease-specific immunoglobulin.

An immunoglobulin specific for RNase [EC 3.1.4.22] has been synthesized in a cell-free system containing either lymph node microsomes or polysomes or spleen polysomes from rats previously immunized with RNase. The synthesis of anti-RNase immunoglobulin was demonstrated by affinity chromatography using an RNase-Sepharose column. Supporting evidence for the cell-free synthesis of immunoglobulin was obtained by separating the synthesized immunoglobulin from other proteins by DEAE-Sephadex A-25 column chromatography and by neutralization of RNase activity with the separated immunoglobulin. Lymph nodes and spleen had an almost equal capacity to synthesize the immunoglobulin to RNase. Under our experimental conditions, 5 to 15 per cent of the total protein synthesis was directed toward immunoglobulin synthesis.