BACKGROUND:  Organizing and separating cells is a fundamental function in the research of biochemical systems. Cell separation methods that utilize electromagnetic forces in particular are useful in research applications, where magnetic beads can be linked with antibodies to ensure specific interaction with target cells. Conventional magnetic cell separator devices require multi-layered, complicated fabrication process to incorporate magnetic materials with the microfluidic channels. Furthermore, high magnetic field gradient are difficult to generate in microfluidic devices such as Micro Total Analysis Systems. The complexity and limitations of the current devices hinders increased utilization of cell separation techniques, prompting a need for a more economical design that would make high-yield separations more accessible to a variety of research applications.

INNOVATION:  A new, optimized microfluidic channel design for maximized cell separation has been developed at UCLA. The device utilizes small metal particles to concentrate magnetic fields, routing the media through a simplified setup that can efficiently separate cells using magnetic beads. The force exerted on the magnetic beads flowing through the new design with the metal particles was markedly increased than a conventional magnet-only setup. The large magnetic field gradient generated from the new design translates into an enhanced magnetic force for cell/bead manipulation or separation.

POTENTIAL APPLICATIONS 

• Efficient cell separation in clinical or research laboratories to replace differential centrifugation separation.
• Isolation or depletion of cells from various starting samples, such as whole blood, spleen, lymph nodes or thymus.
• Sorting of cells to facilitate cell therapies in oncology patients receiving high-dose chemotherapy.

ADVANTAGES

• Simple mechanism is less costly to produce than conventional magnetic cell sorting mechanisms.
• Significant increase in induced magnetic force, with initial results showing the new design with metal particles to be three times as strong as magnet-only setup.
• Proposed technique can be extended in producing high-throughput microfluidic cell separation array, performing multiple cell separation events in one single step.

Reference: UCLA Case No. 2007-477