Hybrid cell sorters for on-chip cell separation by hydrodynamics and magnetophoresis

Abstract

The classification of cells is important for medical diagnosis and medicine research. A micro-scale analysis system for blood allows immediate diagnosis, regardless of time or location. Rapid handling of biological cells is required for the development of lab-on-a-chip and point-of-care technologies. In previous papers, the reported sample solution flow rates for hydrodynamic cell separation ranged from 0.1 to tens of μl min −1 . This paper proposes a hybrid cell sorter that combines hydrodynamics and magnetophoresis. This cell sorter is proposed for improving the classification efficiency of a virtual impactor-based cell sorter and for permitting the hydrodynamic cell separation with high throughput. In addition, its performance has been evaluated in the classification of Jurkat cells and blood cells. In the Jurkat cell experiment, the classification efficiency of Jurkat cells at the major outlet decreased from 70 to 50.8% with the proposed hybrid scheme. The flow rate for cell separation was 1 ml min −1 . The classification efficiency of red blood cells (RBCs) increased from 75.2 to 86.8% with the application of a magnetic field. Also, the classification efficiency of white blood cells (WBCs) decreased from 83.8 to 70.9% with an applied magnetic field. Experimental results demonstrated that the classification efficiency of blood cells can be modulated and enhanced by magnetophoresis and that the hybrid cell sorter has potential for lab-on-a-chip applications.

Numerical Analysis for Magnetophoretic Separation of Blood Cells in Fluid and Magnetic Field

“…5 are tabulated by flow velocity when the electromagnet with a MAP force range of 200 is used (Table I). The collection rate can be calculated using (9).…”

Microfluidic bio-particle manipulation for biotechnology

“…The distance between the magnet pairs can range from tens of m [111] to several mm [75]. Bio-particles can also be manipulated using the magnetic field induced by the permanent magnet on a ferromagnetic wire placed inside the microchannel [112,113]. Additionally, electrodes can also be introduced within the device to switch the magnetic field [65], and to provide high resolution control over positioning of bio-particles [100].…”

“…Due to this special property the RBCs can be separated out from a blood sample under the influence of a strong magnetic field in a microchannel. In this respect, the separation of the components of blood through manipulation of RBCs with magnetic field has been implemented [112,113,138]. A ferro-mangetic wire in the flow path which was magnetized through an external permanent magnet was able to deflect the RBCs where as the WBCs were not affected from the magnetic field.…”

“…A ferro-mangetic wire in the flow path which was magnetized through an external permanent magnet was able to deflect the RBCs where as the WBCs were not affected from the magnetic field. The capture rate of 90% (for the RBCs) and throughput in the order of 10 6 cells/minute have been achieved [113]. The change in magnetic susceptibility of RBCs which are affected from the malaria infection, has also been utilized for the separation of infected RBCs [139].…”

Microfluidic Technology for Cell Manipulation

“…One approach is to combine two individual manipulation methods so that their advantages and disadvantages can be synergized and complemented, respectively [4,5,26,33,[56][57][58][59]. Based on this combination, particles are manipulated by separate mechanisms for each of the two driving sources and a new mechanism derived from the interaction of the two driving forces.…”