Systems and methods for bead-based assays in ferrofluids

A method for assaying a target particle, comprising:

• suspending a plurality of non-magnetic beads in a ferrofluid;
• mixing or otherwise exposing the ferrofluid to a plurality of particles forming a mix, the plurality of particles including one or more target particles;
• flowing the mix such that the ferrofluid carries the non-magnetic beads;
• and
• capturing the one or more target particles.

A bead-based assay ferrofluid apparatus comprising:

• a ferrofluid including a sample containing a mixture of particles and functionalized beads;
• a pump;
• a channel inlet;
• a fluidic channel;
• and
• a magnetic field source comprising at least one of one or more planar electrodes, an electromagnet and a permanent magnet.

A system for extracting a target molecule from a mix of molecules, comprising:

• a plurality of non-magnetic beads suspended in a ferrofluid, the non-magnetic beads being functionalized with at least one predetermined first molecule configured to bind with a target particle;
• a plurality of particles, wherein the plurality of particles arc mixed with the ferrofluid containing the non-magnetic beads resulting in a ferrofluid mix;
• and
• a microfluidic device comprising at least one microfluidic channel, the device configured to dynamically and/or statically receive an amount of the mix;
• magnetic field means configured to:
• apply a magnetic field to at least a portion of the at least one channel to exert an indirect force on the non-magnetic beads in the ferrofluid mix,
• separate the non-magnetic beads from the ferrofluid, and
• direct the non-magnetic beads to at least one receptor region.