Magnetophoresis and cytometry with magnetic microparticles

• Published in: International Congress series Vol. 1300; pp. 271 - 274
• Main Authors: Sandin, H., Carr, C., Matlachov, A.N., Hanson, C.J., Martin, J.C., Ward, M.D., Kraus, R.H., Espy, M.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2007
• Subjects: Magnetic flow cytometer; Magnetic microparticles; Magnetophoresis; Magnetic microparticles; Magnetic flow cytometer; Magnetophoresis
• ISSN: 0531-5131; 1873-6157
• DOI: 10.1016/j.ics.2007.02.004

We are developing a bioassay technique utilizing superparamagnetic and ferromagnetic microparticles, with the aim of using these in biological labeling. The technique uses two independent pieces of instrumentation; a magnetophoresis instrument and a magnetic flow cytometer. The former consists of a microfluidic sorting chamber that incorporates standard flow techniques and a permanent magnet. The particles are deflected into different outlet collection bins, with the degree of deflection determined by the particle's magnetic moment. We report on microparticle sorting and discuss the hydrodynamics of the chamber in relation to reproducibility. Once the microparticles have been sorted, the different populations will then be sequentially analyzed both optically and magnetically (while in flow). The magnetic analysis is presently performed with the aid of a LN 2-cooled high temperature superconducting quantum interference device (HTS SQUID) array. We are currently also evaluating the use of giant magnetoresistive (GMR) sensors. In this paper we will discuss the sorting and resorting of microparticles and present preliminary results for the magnetic detection of the microparticles both with HTS SQUID and GMR sensors.