Membrane affinity apparatus and purification methods related thereto

A method for carrying out affinity purification of a ligate in a hollow fiber membrane system comprising:

• (a) providing a ligate-containing liquid to a first side of at least one microporous hollow fiber defining a membrane, said membrane having a ligand immobilized thereto, said liquid being under a pressure sufficient to cause a first portion of said liquid to flow convectively and tangentially across said first side of said membrane, with a second portion of said liquid being caused to flow convectively into and through said membrane emerging on a second side of said membrane, wherein said ligate present in said liquid binds to said ligand and is thereby separated from said liquid;
• (b) withdrawing said first portion of said liquid from said first side;
• (c) recirculating said withdrawn first portion of said liquid to said first side of said membrane;
• (d) repeating steps (a) to (c) until a majority of said liquid has flowed to the second side;
• and
• (e) providing an elution solution to one side of said membrane under a pressure sufficient to cause said elution solution to flow into and through said membrane and to effect the disassociation of any ligate-ligand bonds, wherein any ligate bound to said ligand is eluted with said elution solution.

An apparatus for carrying out affinity separation comprising:

• at least one porous hollow fiber membrane having a ligand immobilized thereto;
• means for enclosing said at least one porous hollow fiber membrane;
• means for providing a fluid in intimate contact with a first side of said enclosed porous hollow fiber membrane;
• first exit means for directing into a first container any fluid present on a second side of said enclosed porous hollow fiber membrane opposite the first side to which said fluid is first provided according to the fluid providing means;
• and
• second exit means for directing said fluid present on the first side of said membrane into a second container,
• wherein at least part of said fluid leaving from said first exit means has originated from said fluid providing means and said hollow fiber membrane has a substantially isotropic microporous structure in all directions throughout the membrane, with pores large enough to permit convective flow of macromolecule-containing solutions across the hollow fiber membrane.