Open AccessMagnetic field design for selecting and aligning immunomagnetic labeled cells
Author(s) -
Tibbe Arjan G.J.,
de Grooth Bart G.,
Greve Jan,
Dolan Gerald J.,
Rao Chandra,
Terstappen Leon W.M.M.
Publication year - 2002
Publication title -
cytometry
Language(s) - English
Resource type - Journals
eISSN - 1097-0320
pISSN - 0196-4763
DOI - 10.1002/cyto.10060
Subject(s) - magnet , magnetic field , materials science , magnetic separation , polystyrene , line (geometry) , immunomagnetic separation , homogeneous , suspension (topology) , nuclear magnetic resonance , biological system , analytical chemistry (journal) , optics , physics , chromatography , chemistry , polymer , composite material , geometry , biology , mathematics , quantum mechanics , homotopy , pure mathematics , metallurgy , thermodynamics
Background Recently we introduced the CellTracks cell analysis system, in which samples are prepared based on a combination of immunomagnetic selection, separation, and alignment of cells along ferromagnetic lines. Here we describe the underlying magnetic principles and considerations made in the magnetic field design to achieve the best possible cell selection and alignment of magnetically labeled cells. Materials and Methods Computer simulations, in combination with experimental data, were used to optimize the design of the magnets and Ni lines to obtain the optimal magnetic configuration. Results A homogeneous cell distribution on the upper surface of the sample chamber was obtained with a magnet where the pole faces were tilted towards each other. The spatial distribution of magnetically aligned objects in between the Ni lines was dependent on the ratio of the diameter of the aligned object and the line spacing, which was tested with magnetically and fluorescently labeled 6 μm polystyrene beads. The best result was obtained when the line spacing was equal to or smaller than the diameter of the aligned object. Conclusions The magnetic gradient of the designed permanent magnet extracts magnetically labeled cells from any cell suspension to a desired plane, providing a homogeneous cell distribution. In addition, it magnetizes ferro‐magnetic Ni lines in this plane whose additional local gradient adds to the gradient of the permanent magnet. The resultant gradient aligns the magnetically labeled cells first brought to this plane. This combination makes it possible, in a single step, to extract and align cells on a surface from any cell suspension. Cytometry 47:163–172, 2002. © 2002 Wiley‐Liss, Inc.