Patent ID: 9738745
Date: 2017-08-22
CPC Classifications: C08F,C08L,C09D

Claim:
1. A method of purifying a target material from a sample, the method comprising: providing a sample comprising serum or buffer and a target material, wherein the target material is an antibody; providing a magnetic polymer microparticle, wherein the magnetic polymer microparticle has a surface, wherein the surface is covalently attached to a diblock vinylic polymer spacer arm, wherein the diblock vinylic polymer spacer arm comprises a first block polymer and a second block polymer that is different from the first block polymer, wherein the first-block polymer and the second block polymer consist of methacrylate monomers selected from the group consisting of methacrylate, methyl methacrylate, tert-butyl methacrylate and N-hydroxysuccinimide methacrylate, wherein the first block polymer and the second block polymer has 3 to 50 repeating monomer units, wherein the first block polymer is attached at one end to the surface of the magnetic polymer microparticle, wherein the first block polymer comprises functional groups that are-hydrophilic and uncharged at a pH of between 3 to 12, and the second block polymer comprises pendant functional groups that are charged at a pH of between 3 to 12, wherein at least a portion of the pendant functional groups are carboxylic acid groups, and wherein at least one pendant functional group is covalently attached to a binding partner of the target material, wherein the diblock vinylic polymer spacer arm extends outward from the surface of the magnetic polymer microparticle and distances the binding partner from the surface of the magnetic polymer microparticle, wherein the magnetic polymer microparticle comprises greater than 1% by weight of a magnetic material; contacting the sample and the magnetic polymer microparticle, thereby binding the target material to the binding partner, wherein the magnetic polymer microparticle remains suspended in the sample and exhibits reduced agglomeration, reduced non-specific binding, and increased binding affinity to the target material compared to a magnetic polymer microparticle in the absence of the diblock vinylic polymer spacer arm; and magnetically separating the magnetic polymer microparticle bound to the target material from the sample, thereby purifying the target material from the sample.