Serum was obtained from clotted blood in a similar manner

The 2 techniques are based upon the formulation of lead ing ion and trailing ion initially enunciated by Ornstein (3) and lean heavily on the suggestions for buffer strategy made by Williams and Reisfeld (6). The leading ion is po tassium, the trailing ion is fl-alanine in the pH 3.8 system or 3-picoline, (3-methylpyridine) (pK 6.29) in the pH 6.0 system. Acetic acid and cacodylic acid (pK 6.4) provide suitable buffering respectively, for the 2 systems. Precise formulation and comparison of the 2 electrophoretic systems are given in Table 1. Chemicals. The reagents used and their commercial sources were: acrylamide, Canalco, Inc., Rockville, Md.; N,N'-methylenebisacrylamide, N,N,N',N,'-tetramethyl ethylenediamine, and 3-picoline (practical), Eastman Or ganic Chemicals, Rochester, N. Y.; ammonium persulfate, E. C. Apparatus Corp., Philadelphia, Pa.@ ultrapurified urea, Research Plus Labs., Denville, N. J.: sucrose, Sigma Chemical Co., St. Louis, Mo.; fl-alanine and Coomassie Brilliant blue-R-250, Schwarz/Mann, Orangeburg, N. Y.; Amido schwarz (naphthol blue black), Roboz Surgical Instruments Co., Washington, D. C., or Allied Chemical, Morristown, N. J.; Sephadex G-75 and QAE Sephadex A-SO, Pharmacia Fine Chemicals, Piscataway, N. J.; cac odylic acid, ethylenediamine, and Pyronine Y, Fisher Chemicals, New York, N. Y. Plasma Samples. Venous blood was obtained in Versene containing Vacutainer tubes (No. 3300Q: Becton-Dicken son, Rutherford, N. J.) and was placed on ice. The red blood cells were removed by centrifugation in the cold at 800 x g for 20 mm. The plasma supernatant was recentrifuged at