THE SEPARATION OF LARGE DNA FRAGMENTS WITH OSCILLATING MAG- NETIC FIELDS

A NEW METHOD OF SEPARATING LARGE DNA FRAGMENTS INVOLVING OSCILLATING ELECTRIC AND MAGNETIC FIELDS IS BEING STUDIED. THE GOAL OF THIS PROJECT IS TO DEMONSTRATE THE FEASIBILITY OF SEPARATING DNA FRAGMENTS (>500 KB), WHICH IS EXPECTED TO SUBSTANTIALLY IMPROVE THE PROCESS OF SEQUENCING THE HUMAN GENOME. A MOVING CHARGE IN A MAGNETIC FIELD EXPERIENCES A LORENTZ FORCE PERPENDICULAR TO BOTH THE DIRECTION OF THE MOVEMENT AND THE MAGNETIC FIELD. BY APPLYING OSCILLATING CROSSED ELECTRIC AND MAGNETIC FIELDS (OCEMF), BIOLOGICAL PARTICLES WILL DRIFT AT A VELOCITY DEPENDENT ON SIZE AND DIELECTRIC PROPERTIES, AND CAN SUBSEQUENTLY BE SORTED INTO FRACTIONS. THIS EFFECT HAS BEEN DEMONSTRATED ON A VARIETY OF CELLS. A SENSITIVE DEPENDENCY OF THE DRIFT VELOCITY ON THE CELL'S PROPERTIES HAS BEEN OBSERVED. DNA EXHIBITS A LARGE INDUCED DIPOLE MOMENT AT LOW FREQUENCIES WITH A RELAXATION TIME DEPENDENT ON THE LENGTH OF THE FRAGMENT. DNA FRAGMENTS WILL BE INDUCED TO DRIFT UNDER THE INFLUENCE OF OCEMF. BECAUSE THE DRIFT VELOCITY DIRECTION IS ACROSS THE ELECTRIC FIELD, AND THE VELOCITY DEPENDS ON THE LENGTH OF THE FRAGMENT, BETTER SEPARATION CAN BE EXPECTED THAN WITH PULSED FIELD ELECTROPHORESIS.