The amino-acids and other ampholytes of urine. 1. A general method of isolation

Abstract

A procedure is descr. whereby the amino acids and other ampholytes may be separated from other urine constituents and to some extent from each other. The primary separation is carried out on columns of the cation-exchange resin Zeo-Karb 215. Selected fractions from the initial separation are then refractionated on columns of the anion-exchange resin Dowex 2. In this way the ampholytes, as a group, are concentrated in a number of arbitary fractions and a large degree of resolution of the complex mixture is also obtained. The selection of fractions in which any one amino acid of special interest occurs provides a rich source for the final isolation of this substance. The order in which the "non-alpha" amino acids are displaced from a column of the strongly basic resin Dowex 2 is discussed.