Patent ID: 7892856

Claim:
A method comprising: providing a fluid flow path, the fluid flow path having first and second ends, a fluid flow controller effective to variably impose a positive or negative pressure on the flow path to cause controlled fluid flow through the fluid flow path in a first or second direction at predetermined rates, and a capture zone between the first and second ends, wherein a fixed magnetic field intercepts the fluid flow path in the capture zone; providing in the fluid flow path a first mixture including a plurality of solid magnetic particles dispersed in a carrier medium; passing the first mixture through the capture zone at a first predetermined capture rate whereby a major portion of the magnetic particles become trapped in the capture zone by the force of the magnetic field and thereby separated from the carrier medium to form a first magnetic particle isolate; perfusing the first magnetic particle isolate with a first dispersion medium; and pulsing the first dispersion medium through the capture zone at a first predetermined dispersion rate effective to dislodge the first magnetic particle isolate from the capture zone, move the magnetic particles from the magnetic field, and suspend the magnetic particles in the first dispersion medium to provide a second mixture.