In this work affinity membrane adsorbers were investigated for the chromatographic purification of recombinant human erythropoietin (rhEPO) produced in mammalian cells. Cibacron Blue (CB), IDA-Cu+2, wheat germ agglutinin (WGA), concanavalin A (ConA) and an anti-EPO monoclonal antibody (MAb) were tested as affinity ligands, attached to microporous Sartobind (R) membranes. In experiments carried out with cell culture supernatant, the best results were obtained with Sartobind-CB, Sartobind-WGA and Sartobind-MAb membranes. The thermodynamic parameters were determined by adsorption isotherms of rhEPO onto the membranes. Sartobind-ConA presented the lowest affinity for rhEPO, as evidenced by a lower association constant. For Sartobind-CB, Sartobind-IDA-Cu+2 and Sartobind-MAb K-A was in the order of 10(5) L mol(-1), whereas for Sartobind-WGA it was 10(6) L mol(-1). Sartobind-CB eluates were also investigated by RP-HPLC. The purity level achieved in this one-step purification strategy was 55%, indicating that the Sartobind-CB membrane is a promising affinity membrane for rhEPO purification. (c) 2007 Society of Chemical Industry.