Patent ID: 8426214

Claim:
A method for concentrating a non-magnetic particle in a liquid, comprising: (a) applying a magnetic field to a mixture comprising a co-aggregate in a liquid to provide a collected co-aggregate in the liquid, wherein the co-aggregate comprises: (i) a magnetic particle having a stimuli-responsive polymer attached thereto; and (ii) a non-magnetic particle having a stimuli-responsive polymer attached thereto; wherein the non-magnetic particle further comprises a first binding partner of a binding pair, wherein the liquid comprises a second binding partner of the binding pair, and wherein the co-aggregate comprises a non-magnetic particle having the first and second binding partners attached thereto; (b) removing at least a portion of the liquid from the collected co-aggregate in the liquid; (c) re-dissolving the co-aggregate to provide a mixture comprising the magnetic particle having the stimuli-responsive polymer attached thereto and the non-magnetic particle having the stimuli-responsive polymer and first and second binding partners attached thereto; and (d) contacting the mixture comprising the magnetic particle having the stimuli-responsive polymer attached thereto and the non-magnetic particle having the stimuli-responsive polymer and first and second binding partners attached thereto with a solid phase effective to immobilize the non-magnetic particle having the stimuli-responsive polymer and first and second binding partners attached thereto.