Magnetophoresis-Integrated Hydrodynamic Filtration System for Size- and Surface Marker-Based Two-Dimensional Cell Sorting

Abstract

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.

New advances in microfluidic flow cytometry

“…Recently, Mizuno et al. reported a sorting system by combining integrating hydrodynamic filtration and magnetophoresis. This method reached up to 90% purification ratios in the sorting of cell mixtures.…”

Advances in steady-state continuous-flow purification by small-scale free-flow electrophoresis

“…Free-flow magnetophoresis separates particle analytes from a stream of sample, which is driven continuously through a magnetic field and typically orientated orthogonally to the flow. Magnetophoresis, in free-flow form, has been applied to the separation of cancer cells from normal cells [17,18], DNA purification [19], water purification [20,21], and nanoparticle (NP) purification [22].…”

Staggered-electromagnetophoresis with a Split-flow System for the Separation of Microparticles by a Hollow Fiber-embedded PDMS Microchip

“…[6][7][8][9][10] First, the particles injected by the flow into a microchip are focused or concentrated positionally in the focusing segment, and then separated based on their size or properties by a force against or across the flow induced by multiple streams, such as designed structures of the microchannel and applied fields in the separation segment. Finally, they are individually collected from two or more outlets at the fractionation segment.…”

“…Finally, they are individually collected from two or more outlets at the fractionation segment. A hydrodynamic focusing technique such as sheath flow has been often used to focus the particles, and migration techniques of the particles, such as electrophoresis, 11,12 dielectrophoresis (DEP), 9,13-15 magnetophoresis, [16][17][18] acoustophoresis, [19][20][21] dean flow, 22 pinched flow fractionation (PFF), 10,23 and split-flow thin (SPLITT) fractionation, [24][25][26] have been utilized to separate them based on the difference of their migration velocities in the flow. Among them, the method in which the particles are separated in the orthogonal direction to the flow and fractioned at each outlet is called a free-flow technique.…”