Methods of isolating bispecific antibodies

The present invention relates to methods of isolating bispecific antibodies or bispecific antibody fragments. The method comprises the steps of: a) providing a feed comprising a bispecific antibody or a bispecific antibody fragment; b) contacting the feed with a separation matrix having an affinity ligand coupled to a carrier; c) optionally washing the separation resin with a washing liquid; d) applying an elution buffer to the separation resin to elute the antibody or antibody fragment bound to the affinity ligand; wherein in step d) a pH gradient is applied to the elution buffer, the pH gradient being from about 6 to about 2. 本发明涉及分离双特异性抗体或双特异性抗体片段的方法。该方法包括以下步骤：a)提供包含双特异性抗体或双特异性抗体片段的进料；b)使所述进料与具有与载体偶联的亲和配体的分离基质接触；c)任选地用洗涤液洗涤分离树脂；d)将洗脱缓冲液施加到分离树脂，以洗脱与亲和配体结合的抗体或抗体片段；其中在步骤d)中，对洗脱缓冲液施加pH梯度，所述pH梯度为从约6至约2。