Lewis G. Longsworth

THE ELECTROPHORETIC ANALYSIS OF MATERNAL AND FETAL PLASMAS AND SERA

obtained by different workers for a given type of material are not in quantitative agreement, the results of any one research are consistent in indicating certain systematic differences between bloods from the three sources. Thus, the concentration, Ps, of serum protein in fetal blood is lower than in that of normal adults. The ratio, PA/PO, of albumin to globulin is, on the other hand, not very different in the two cases. Finally, maternal blocds, taken during the later stages of pregnancy or at term, tend to have a concentration of total serum protein that is not very different from the normal values but in which the albumin-globulin ratio is low. In obtaining these results, the solubility of albumin, globulin, and fibrinogen in aqueous salt solutions was used for the separation of these plasma fractions. This method does not distinguish.between the antibody globulins and the immunologically inactive globulins. In view of the evidence (4) as to the considerable immunity possessed by the new-born infant, it appeared that it would be of interest to obtain this additional information. Electrophoresis by the Tiselius procedure (5) affords a new and effective method for the analysis of serum or plasma and permits the separation of plasma globulin into at least four electrophoretically distinguishable components exclusive of fibrinogen (6). While there is no reason to think that the y globulin of Tiselius consists wholly of immune bodies, there is much evidence (7) that these bodies are y globulins. It is the purpose of this paper to report the results of the electrophoretic analyses of ten pairs of plasmas, or sera, taken from the placenta and the mother at the time of child birth and to compare the values thus obtained with each other and with those for normal adults (8).