Microfabricated Flow System for Magnetic Cell and Particle Separation

  • Gert Blankenstein


A new microchannel-based system for continuous separation of magnetizable particles is presented, with possible applications in cell and particle separation, immunoassays, receptor assays or affinity purification. The presented system offers the novel possibility to handle, entrap and sort small volumes of cell samples in a continuous or stopped-flow regime. By using a microfabricated flow chip with integrated permanent or electromagnets, magnetizable particles can be sorted in a one-step procedure. The magnetic field does not have to be removed and no washing steps are necessary. The microchannels of the flow chip are etched into silicon and covered with a transparent glass plate, allowing external optical observation and detection of the liquids inside the microchannels using a microscope. In that respect the optomagnetic flow cytometry system combines both optical characterization of cells or particles and magnetic separation. An apparatus for magnetic separation including a system of valves, syringe pumps and the flow chip has been designed and used for initial experiments. The simply equipped and portable sorting system has been automated for magnetic particle separation. The suitability of the flow chip was demonstrated by the separation of paramagnetic particles and living cells. Enrichment rates of more than 300-fold can be achieved.


Magnetic Particle Separation Flow Magnetic Separation Volumetric Flow Rate Particle Separation 
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  1. 1.
    Parks DR, Lanier LL, Herzenberg LA (1986). Flow cytometry and fluorescence activated cell sorting (FACS). In Handbook of experimental immunology, 4th edition, Weir DM ( Ed. ). Blackwell Scientific Publications, Oxford.Google Scholar
  2. 2.
    Melamed MP, Lindmo T, Mortimer ML Mendelsohn (Eds) (1991). Flow Cytometry and sorting. 2nd edition, John Wiley & Sons, Inc.Google Scholar
  3. 3.
    Jones TB (1995). Electromechanics of particles. Cambridge University Press.Google Scholar
  4. 4.
    Uhlen M, Homes E, Olsvik 0 (Eds.) (1994). Advances in biomagnetic separation. Eaton Publishing Co.Google Scholar
  5. 5.
    Bianchi, DW (1994). Clinical Trials and Experience. Annals of the New York Academy of Sciences 731, 92–102.ADSCrossRefGoogle Scholar
  6. 6.
    Campana D (1994). Applications of cytometry to study acute leukemia: In vitro determination of drug sensitivity and detection of minimal residual disease. Cytometry 18 68–74.CrossRefGoogle Scholar
  7. 7.
    Harbeck N (1996). Model for isolation of competent ovarian carcinoma cells from fresh tumor tissue by magnetic separation technique. Int. J. Oncology 6 1249–1254.Google Scholar
  8. 8.
    George F (1992). Bone marrow purging and suppressing. Thrombosis and Haemostasis 67 147.Google Scholar
  9. 9.
    Ploem-Zaaijer JJ, Mesker WE, Boland GJ, Sloos WC, van de Rijke FM, Jiwa M, Raap AK (1994). Automated Image Cytometry for Detection of Rare, Viral Antigen-Positive Cells in Peripheral Blood. Cytometry 15, 199–206.Google Scholar
  10. 10.
    Melville D, Paul F, Roath S (1975). Direct magnetic separation of red blood cells from whole blood. Nature 255, 706–708.CrossRefGoogle Scholar
  11. 11.
    Miltenyi S, Mueller W, Weichel W, Radbruch A (1990). High Gradient Magnetic Cell Separation With MACS. Cytometry 11, 231–238.Google Scholar
  12. 12.
    Manyonda IT, Soltys AJ, Hay FC (1992). A critical evaluation of the magnetic cell sorter and its use in the positive and negative selection of CD45RO+ cells. J. Immunol. Methods 149, 1–10.Google Scholar
  13. 13.
    Purcell EM (1977). Life at low Reynolds number. American Journal of Physics 45 3-l.Google Scholar
  14. 14.
    Larsen UD Blankenstein G, Branebjerg J (1996). A novel design in construction of chemical and biochemical liquid analysis sytem. 1sTAS ‘86,19–22 November 1996.Google Scholar
  15. 15.
    Blankenstein G, Scampavia LD, Ruziecka J, Christian GD (1996). Coaxial Flow Mixer for Real-Dme Monitoring of Cellular Responses in Flow Injection Cytometry. Cytometry 25, 200–204.Google Scholar
  16. 16.
    Blankenstein G, Scampavia L, Branebjerg J, Larsen UD, Ruzicka J (1996). Flow switch for analyte injection and cell/particle sorting. In Analytical Methods and Instrumentation. µTAS ‘96 conference, 17–22 November 1996, Basel.Google Scholar

Copyright information

© Springer Science+Business Media New York 1997

Authors and Affiliations

  • Gert Blankenstein
    • 1
  1. 1.Mikroelektronik Centret (MIC)Technical University of DenmarkLyngbyDenmark

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