Tibbe Arjan G J, de Grooth Bart G, Greve Jan, Dolan Gerald J, Rao Chandra, Terstappen Leon W M M
Biophysical Techniques Group, Faculty of Applied Physics, Twente University, PO Box 217, 7500 AE Enschede, The Netherlands.
Cytometry. 2002 Mar 1;47(3):163-72. doi: 10.1002/cyto.10060.
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.
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 microm polystyrene beads. The best result was obtained when the line spacing was equal to or smaller than the diameter of the aligned object.
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.
最近我们推出了CellTracks细胞分析系统，该系统基于免疫磁选、细胞分离以及细胞沿铁磁线排列的组合来制备样品。在此，我们描述其潜在的磁学原理以及在磁场设计中为实现最佳细胞选择和磁性标记细胞排列所做的考量。材料与方法结合计算机模拟和实验数据来优化磁体和镍线的设计，以获得最佳磁配置。
使用磁极面相互倾斜的磁体，在样品腔上表面获得了均匀的细胞分布。镍线之间磁性排列物体的空间分布取决于排列物体的直径与线间距的比例，这通过磁性和荧光标记的6微米聚苯乙烯珠进行了测试。当线间距等于或小于排列物体的直径时，获得了最佳结果。
设计的永磁体的磁梯度将磁性标记的细胞从任何细胞悬液中提取到所需平面，提供均匀的细胞分布。此外，它使该平面中的铁磁性镍线磁化，其额外的局部梯度增加了永磁体的梯度。由此产生的梯度使首先带到该平面的磁性标记细胞排列整齐。这种组合使得能够一步从任何细胞悬液中提取细胞并使其在表面排列整齐。
