Modelling immunomagnetic cell capture in CFD

The separation of cells from a complex sample by immunomagnetic capture has recently obtained increased attention for microfluidic applications. Here, we present a simulation approach for immunomagnetic separation in a flow-through microfluidic environment that for the first time takes binding kinetics of beads to target cells as well as binding of multiple beads per cell into account. The approach is implemented into a computational fluid dynamics code and facilitates the tailored design of microfluidic magnetophoretic devices with an optimised separation performance. Although the specific computational model under study is constrained to a 2D geometry, appropriate parameter sets that allow for a continuous separation of cell/bead complexes from non-magnetic particles could be derived. In addition, based on magnetophoretic mobilities, a critical threshold value of beads per cell is revealed, where further binding is considerably reduced or the reaction cascade ceases.