Biomedical Microdevices

, 8:299

Combined microfluidic-micromagnetic separation of living cells in continuous flow

  • Nan Xia
  • Tom P. Hunt
  • Brian T. Mayers
  • Eben Alsberg
  • George M. Whitesides
  • Robert M. Westervelt
  • Donald E. Ingber
Article

DOI: 10.1007/s10544-006-0033-0

Cite this article as:
Xia, N., Hunt, T.P., Mayers, B.T. et al. Biomed Microdevices (2006) 8: 299. doi:10.1007/s10544-006-0033-0

Abstract

This paper describes a miniaturized, integrated, microfluidic device that can pull molecules and living cells bound to magnetic particles from one laminar flow path to another by applying a local magnetic field gradient, and thus selectively remove them from flowing biological fluids without any wash steps. To accomplish this, a microfabricated high-gradient magnetic field concentrator (HGMC) was integrated at one side of a microfluidic channel with two inlets and outlets. When magnetic micro- or nano-particles were introduced into one flow path, they remained limited to that flow stream. In contrast, when the HGMC was magnetized, the magnetic beads were efficiently pulled from the initial flow path into the collection stream, thereby cleansing the original fluid. Using this microdevice, living E. coli bacteria bound to magnetic nanoparticles were efficiently removed from flowing solutions containing densities of red blood cells similar to that found in blood. Because this microdevice allows large numbers of beads and cells to be sorted simultaneously, has no capacity limit, and does not lose separation efficiency as particles are removed, it may be especially useful for separations from blood or other clinical samples. This on-chip HGMC-microfluidic separator technology may potentially allow cell separations to be carried out in the field outside of hospitals and clinical laboratories.

Keywords

Nanotechnology Bioseparations Microfluidics Magnetic particles Bacteria Magnetic field gradient concentrator 

Copyright information

© Springer Science + Business Media, LLC 2006

Authors and Affiliations

  • Nan Xia
    • 1
  • Tom P. Hunt
    • 3
  • Brian T. Mayers
    • 4
  • Eben Alsberg
    • 1
    • 2
  • George M. Whitesides
    • 4
  • Robert M. Westervelt
    • 3
  • Donald E. Ingber
    • 1
  1. 1.Vascular Biology Program, Departments of Pathology & Surgery, Karp Family Research LaboratoriesChildren's Hospital and Harvard Medical SchoolBostonUSA
  2. 2.Department of Biomedical EngineeringCase Western Reserve UniversityClevelandUSA
  3. 3.Department of Physics and Division of Engineering and Applied SciencesHarvard UniversityCambridgeUSA
  4. 4.Department of Chemistry and Chemical BiologyHarvard UniversityCambridgeUSA

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