In this work, new and feasible magnetic particles were prepared in uniform and spherical form for a diameter range of 125 to 250 mu m from a commercial resin Mowital(R) B30HH (polyvinyl butyral) through a modified solvent evaporation technique. For the production of particles, the most appropriate solvent, stabilization and surface active agents, and stirring rate were determined as chloroform, SDS, pluronic F68 together with PVA and 700 rev./min, respectively. The magnet abundant in nature, magnetite (mean diameter < 40 mu m), was successfully embedded in the particle structure during polymerization by an elaborate technique and spherical particles with high magnetic quality were realized for possible magnetically fluidized bed or magnetic filtration applications. FTIR studies proved the abundance of hydroxyl groups on the particle surface, which were activated later by glutaraldehyde for bioaffinity separations. Preliminary adsorption runs were conducted with magnetic and non-magnetic microbeads for bovine serum albumin which resulted in remarkable adsorption capacities as high as 86 mg protein per g of magnetic microbeads. (C) 2000 Elsevier Science B.V. All rights reserved.