Microfluidic Platform for Sorting and Manipulation of Single Magnetic Particles and Biomolecules

PIs: Victor M. Bright, John Moreland (NIST)
Student: Wendy R. Krauser

Project field/specialty: Micro-fluidics, Magnetic Tweezers

Project Description:

Manipulation of chemical and biological species on a microscale is an important technique used in biotechnology, microanalysis, microsynthesis, and similar technologies. High gradient magnetic separation is a long established procedure for selectively retaining magnetic materials in a chamber or column disposed in a magnetic field. In the last two decades, this technique has also been applied to non-magnetic targets such as biological molecules that are ligated to magnetic particles. In the presence of the magnetic gradient, the magnetically labeled target analyte is retained while materials that do not have magnetic labels flow through the chamber or column. The retained target can then be manipulated (see Figure 1). Our approach to magnetic separation is to use a microfluidic platform that incorporates a thin micromachined membrane consisting of an array of spin-valves (microfabricated, switchable, permanent magnets) to selectively trap, manipulate and release magnetic particles with high throughput and specificity (Figure 2). The platform may be used in a variety of applications including drug screening, nucleic acid sequencing, structural control and analysis of RNA/DNA, medical diagnosis, and magnetic particle susceptibility and size homogenization for medical applications.

This project is a continuation of E. Morowski's work.

Figure 1: Stretching of DNA attached to two magnetic particles under the influence of a magnetic field (Picture courtesy of E. Morowski)


Figure 2: Microfluidic magnetic array developed by E. Morowski et al.

Funding Source: NIST

References:

• Mirowski, E., Moreland, J., Russek, S.E. (2004) Integrated microfluidic isolation platform for magnetic particle manipulation in biological systems Appl. Phys. Lett., Vol. 84(10):1786-1788.

Last Updated: February 2008