SITES OF FORMATION OF IMMUNE GLOBULINS AND OF A COMPONENT OF C'(3): I. A NEW TECHNIQUE FOR THE DEMONSTRATION OF THE SYNTHESIS OF INDIVIDUAL SERUM PROTEINS BY TISSUES IN VITRO.

The development of a new method for the determination of the sites of serum protein formation has been described. The method involves the incorporation of C(14)-labeled amino acids by tissues cultured in vitro, and subsequent autoradiography of immunoelectrophoretic patterns prepared from a mixture of culture fluids and carrier serum with an antiserum against the carrier serum. This technique has been used to demonstrate formation of gamma-globulin, of beta(2)-macroglobulin, and of a component of C'(3) by mouse spleen tissue, and of various other serum proteins by liver tissue. The specificity and sensitivity of this method have been discussed, and some of its advantages and pitfalls were mentioned. In addition, a rabbit antimouse serum was prepared, and the immunoelectrophoretic patterns obtained with mouse serum were compared with those described in the literature.