Preliminary studies using pure human serum antibodiesand fetal bovine serum showed that heparin can be used as a cation exchanger for the capture of antibod-ies. Different adsorption and elution buffers were screened and the most promising results were obtainedusing 20 mM phosphate buffer at pH 8.0 as binding buffer and 1 M NaCl in 20 mM phosphate buffer atpH 8.0 as elution buffer.