The document pertains to a method for the purification of a ternary mixture of dimeric antibodies of the type AA, AB, BB, characterized in that for the separation of the three components and in particular for the isolation of the multi-specific fraction AB multicolumn counter current solvent gradient purification chromatography with a stationary phase load of more than 1 mg antibody mixture per milliliter stationary phase is used. It furthermore relates to a method for the identification of in particular bispecific antibody systems, which are particularly suitable for the application of such a purification method.