Magnetophoresis-integrated hydrodynamic filtration system for size- and surface marker-based two-dimensional cell sorting.

A simple microfluidic system has been presented to perform continuous two-parameter cell sorting based on size and surface markers. Immunomagnetic bead-conjugated cells are initially sorted based on size by utilizing the hydrodynamic filtration (HDF) scheme, introduced into individual separation lanes, and simultaneously focused onto one sidewall by the hydrodynamic effect. Cells are then subjected to magnetophoretic separation in the lateral direction, and finally they are individually recovered through multiple outlet branches. We successfully demonstrated the continuous sorting of JM (human lymphocyte cell line) cells using anti-CD4 immunomagnetic beads and confirmed that accurate size- and surface marker-based sorting was achieved. In addition, the sorting of cell mixtures was performed at purification ratios higher than 90%. The proposed system enables two-dimensional cell sorting without necessitating complicated setups and operations, and thus, it can be a useful tool for general biological experiments including cell-based disease diagnosis, stem cell engineering, and cellular physiological studies.