Continuous sorting of magnetic cells via on-chip free-flow magnetophoresis

TLDR

Separating living cells is essential for cell research, and magnetic methods are among the most efficient for bulk separation, especially with microfluidic miniaturization. This study reports continuous sorting of magnetic nanoparticle‑loaded cells in a microfluidic magnetic separation device. Cells were flowed through a microfluidic chamber and deflected by a magnetic field; the device was tested on mouse macrophages and human HeLa cells. Deflection depended on cell magnetic moment, size, and flow rate, matched calculations, and enabled separation of magnetic and non‑magnetic cells.

Abstract

The ability to separate living cells is an essential aspect of cell research. Magnetic cell separation methods are among some of the most efficient methods for bulk cell separation. With the development of microfluidic platforms within the biotechnology sector, the design of miniaturised magnetic cell sorters is desirable. Here, we report the continuous sorting of cells loaded with magnetic nanoparticles in a microfluidic magnetic separation device. Cells were passed through a microfluidic chamber and were deflected from the direction of flow by means of a magnetic field. Two types of cells were studied, mouse macrophages and human ovarian cancer cells (HeLa cells). The deflection was dependent on the magnetic moment and size of the cells as well as on the applied flow rate. The experimentally observed deflection matched well with calculations. Furthermore, the separation of magnetic and non-magnetic cells was demonstrated using the same microfluidic device.