METHOD FOR PRODUCING HIGHLY PURIFIED OBJECTIVE SUBSTANCE FROM MIXTURE

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently isolating the objective substance from a mixture comprising protein, peptide and amino acids to obtain the objective substance of improved purity. SOLUTION: This method for isolating the objective substance by electrodialysis method from a mixture of amphoteric electrolytes differing in isoelectric point from each other such as lysine and methionine comprises carrying out an electrodialysis of the mixture under a pH condition equivalent to the isoelectric pH region or isoelectric point of either the objective component or impurity components, or under a pH condition so as to be >=1 in the difference between the difference between the solution pH and the isoelectric point of the objective substance and the difference between the solution pH and the isoelectric point of the impurities in carrying out the electrodialysis, thus isolating the objective component to obtain the objective component of improved purity.