title: Red blood cell magnetophoresis.
abstract: The existence of unpaired electrons in the four heme groups of deoxy and methemoglobin (metHb) gives these species paramagnetic properties as contrasted to the diamagnetic character of oxyhemoglobin. Based on the measured magnetic moments of hemoglobin and its compounds, and on the relatively high hemoglobin concentration of human erythrocytes, we hypothesized that differential migration of these cells was possible if exposed to a high magnetic field. With the development of a new technology, cell tracking velocimetry, we were able to measure the migration velocity of deoxygenated and metHb-containing erythrocytes, exposed to a mean magnetic field of 1.40 T and a mean gradient of 0.131 T/mm, in a process we call cell magnetophoresis. Our results show a similar magnetophoretic mobility of 3.86 x 10(-6) mm(3) s/kg for erythrocytes with 100% deoxygenated hemoglobin and 3.66 x 10(-6) mm(3) s/kg for erythrocytes containing 100% metHb. Oxygenated erythrocytes had a magnetophoretic mobility of from -0.2 x 10(-6) mm(3) s/kg to +0.30 x 10(-6) mm(3) s/kg, indicating a significant diamagnetic component relative to the suspension medium, in agreement with previous studies on the hemoglobin magnetic susceptibility. Magnetophoresis may open up an approach to characterize and separate cells for biochemical analysis based on intrinsic and extrinsic magnetic properties of biological macromolecules.
authors.affiliation: Department of Biomedical Engineering/ND20, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44915, USA. zborow@bme.ri.ccf.org
authors.forename: Maciej
authors.initials: M
authors.lastname: Zborowski
authors.forename: Graciela R
authors.initials: GR
authors.lastname: Ostera
authors.forename: Lee R
authors.initials: LR
authors.lastname: Moore
authors.forename: Sarah
authors.initials: S
authors.lastname: Milliron
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Chalmers
authors.forename: Alan N
authors.initials: AN
authors.lastname: Schechter
mesh_terms: D002465:Cell Movement / Q000502:physiology* / Q000528:radiation effects*; D002469:Cell Separation / Q000379:methods; D004574:Electromagnetic Fields; D004912:Erythrocytes / Q000502:physiology* / Q000528:radiation effects*; D006454:Hemoglobins / Q000528:radiation effects*; D006801:Humans; D008280:Magnetics; D010108:Oxyhemoglobins / Q000528:radiation effects; D012212:Rheology / Q000295:instrumentation / Q000379:methods*
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins