Continuous-flow in-droplet magnetic particle separation in a droplet-based microfluidic platform
- 1.1k Downloads
This paper presents a continuous-flow in-droplet magnetic particle separation in a droplet-based microfluidic device for magnetic bead-based bioassays. Two functions, electrocoalescence and magnetic particle manipulation, are performed in this device. A pair of charging metallic needles is inserted into two aqueous channels of the device. By electrostatic force, two different solutions can be merged to be mixed at a junction of droplet generation. The manipulation of magnetic particles is achieved using an externally applied magnetic field. The magnetic particles are separated by the magnetic field to one side of the droplet and extracted by splitting the droplet into two daughter droplets: one contains the majority of the magnetic particles and the other is almost devoid of magnetic particles. The applicability of the continuous-flow in-droplet magnetic particle separation is demonstrated by performing a proof-of-concept immunoassay between streptavidin-coated magnetic beads and biotin labelled with fluorescence. This approach will be useful for various biological and chemical analyses and compartmentalization of small samples.
KeywordsMagnetic particle manipulation Magnetic field Magnetic bead assay Droplet merging Droplet splitting
This work was supported by the National Science Foundation grants (Grant Nos. ECCS-1002255 and ECCS-0736501).
- Wang C, Oleschuk R, Ouchen F, Li JJ, Thibault P, Harrison DJ (2000) Integration of immobilized trypsin bead beds for protein digestion within a microfluidic chip incorporating capillary electrophoresis separations and an electrospray mass spectrometry interface. Rapid Commun Mass Spectrom 14:1377–1383CrossRefGoogle Scholar
- Ward T, Faivre M, Abkarian M, Stone HA (2005) Microfluidic flow focusing: drop size and scaling in pressure versus flow-rate-driven pumping. Electrophoresis 26:3716–3724Google Scholar