Monodisperse poly(glycidyl methacrylate) (m-PGMA) microspheres which show superparamagnetic behaviour were synthesized by dispersion polymerization. Bioligand protein A was covalently immobilized onto glutaraldehyde activated microspheres (3.12 mg protein A per gram of microspheres). Cell culture studies denoted that 61% of total L929 mouse fibroblasts were bound to the m-PGMA microspheres while 84% of total cells were bounding to the protein A immobilized (m-PGMA-PrA) microspheres. Interactions between m-PGMA-PrA microspheres and L929 cells were stronger than that of m-PGMA microspheres due to the non-specific interactions between protein A and cell surface. The cells interacted with m-PGMA-PrA microspheres keep their round form rather than attaching to the tissue culture polystyrene (TCPS) surface. In conclusion, this study consists a basis for the fractionation of blood lymphocytes bearing IgG antibodies on their surfaces by using protein A immobilized m-PGMA microspheres. (C) 2009 Elsevier Ltd. All rights reserved.