Patent ID: 8481694

Claim:
A method of purifying an antibody-agent conjugate from unconjugated antibody and unconjugated agent, wherein the antibody is an IgG and the agent comprises phycoerythrin, the method comprising, (a) contacting a mixture of conjugate, unconjugated antibody, and unconjugated agent to a mixed mode chromatography support under conditions to allow binding of the conjugate, unconjugated antibody, and unconjugated agent to the support; (b) contacting the support with a buffer, the contacting comprising an increased concentration of salt such that the unconjugated antibody and unconjugated agent are substantially removed from the support while at least a majority of the conjugate remains bound to the support; and then (c) eluting the conjugate from the support, wherein the eluting comprises increasing the concentration of the buffer, thereby purifying the antibody-agent conjugate from unconjugated antibody and unconjugated agent.