Wu Meiling, Yadav Rajeev, Pal Nibedita, Lu H Peter
Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
Rev Sci Instrum. 2017 Jul;88(7):073703. doi: 10.1063/1.4995362.
Controlling and manipulating living cell motions in solution hold a high promise in developing new biotechnology and biological science. Here, we developed a magnetic tweezers device that employs a combination of two permanent magnets in up-down double-ring configuration axially fitting with a microscopic objective, allowing a picoNewton (pN) bidirectional force and motion control on the sample beyond a single upward pulling direction. The experimental force calibration and magnetic field simulation using finite element method magnetics demonstrate that the designed magnetic tweezers covers a linear-combined pN force with positive-negative polarization changes in a tenability of sub-pN scale, which can be utilized to further achieve motion manipulation by shifting the force balance. We demonstrate an application of the up-down double-ring magnetic tweezers for single cell manipulation, showing that the cells with internalized paramagnetic beads can be selectively picked up and guided in a controlled fine motion.
在溶液中控制和操纵活细胞运动在开发新的生物技术和生物科学方面具有很大的前景。在此，我们开发了一种磁镊装置，该装置采用上下双环配置的两个永久磁铁组合，轴向与显微镜物镜适配，从而能够对样品施加皮牛顿（pN）双向力并进行运动控制，而不仅仅局限于单一的向上拉伸方向。使用有限元方法磁学进行的实验力校准和磁场模拟表明，所设计的磁镊涵盖了在亚皮牛顿尺度的可控范围内具有正负极化变化的线性组合皮牛顿力，通过改变力平衡可进一步用于实现运动操纵。我们展示了上下双环磁镊在单细胞操纵中的应用，表明内化了顺磁珠的细胞能够被选择性地拾取并以受控的精细运动进行引导。
