Implementation and application of a novel 2D magnetic twisting cytometry based on multi pole electromagnet.
We implemented a novel 2D magnetic twisting cytometry (MTC) based on a previously reported multi pole high permeability electromagnet, in which both the strength and direction of the twisting field can be controlled. Thanks to the high performance twisting electromagnet and the heterodyning technology, the measurement frequency has been extended to the 1 kHz range. In order to obtain high remanence of the ferromagnetic beads, a separate electromagnet with feedback control was adopted for the high magnetic field polarization. Our setup constitutes the first instrument which can be operated both in MTC mode and in magnetic tweezers (MT) mode. In this work, the mechanical properties of HL 1 cardiomyocytes were characterized in MTC mode. Both anisotropy and log normal distribution of cell stiffness were observed, which agree with our previous results measured in MT mode. The response from these living cells at different frequencies can be fitted very well by the soft glassy rheology model.
The Review of scientific instruments