The Formation of Myeloma Protein by a Mouse Plasma Cell Tumor

The origin of the myeloma protein found in mice bearing the plasma cell tumor X5563 has been investigated. Specific activity-time curves of the myeloma proteins isolated from the tumor and from the plasma of these animals were compared following intravenous injection of L-lysine-C(14). The results indicate that myeloma protein is synthesized in the plasma cell tumor.