A new method of binding bovine serum albumin on to freshly precipitated magnetic particles is reported. The binding was confirmed by electron micrograph studies, magnetic measurements and FTIR spectroscopy. Under optimum conditions more than 90% of the protein was bound to the magnetic particles. When alkaline phosphatase was immo-bilised using this method, it retained 75% enzyme activity. The method may prove to be applicable to radio-immuno assays (binding of antibodies to magnetic particles), cell and enzyme immobilisation and in affinity chromatography.