The US Patent and Trademark Office has granted MDS Proteomics US Patent 6,423,410, covering the composition and method for generating paramagnetic polymer particles for use in affinity separation of ligands. In this particular invention, entitled “Ultrasonically Generated Paramagnetic Polymer Particles,” the vinyl monomers are polymerized in the presence of high energy ultrasound. The particles contain vacuous cavities, a high percentage of evenly distributed magnetite, and are stable in both aqueous and organic solvents.