The SPHERO™ Magnetic Particles are prepared by coating a layer of magnetite and polystyrene onto monodispersed (i.e.. uniform sized) polystyrene core particles. As a result, the SPHERO™ Magnetic Particles are spherical in shape, and paramagnetic in nature. They are also very uniform in size. The magnetite contents of these magnetic particles can be adjusted but in general it represents about 10% to 15% for 1 micron particles. The magnetic particles can be easily separated from a suspension magnetically. These particles become non-magnetic when removed from a magnet, and do not retain any detectable magnetism even after repeated exposure to strong magnetic field. The SPHERO™ Magnetic Particles can be used for cell separation, affinity purification, DNA probe assays, magnetic particle EIA, etc. For more information please see Using Magnetic Microparticles in Molecular and Cellular Isolations.