Determination of human erythropoietin by on-line immunoaffinity capillary electrophoresis: a preliminary report

Several CE methodologies have been described for the analysis of rHuEPO in concentrated solutions, but the inherently limited concentration sensitivity of CE precludes the detection of EPO at the levels found in biological fluids. In this work, we have investigated an on-line immunoaffinity solid-phase extraction capillary electrophoresis (IA-CE) methodology for the selective preconcentration of EPO in diluted solutions. The preliminary results obtained using a custom-made immunoaffinity sorbent prepared from an anti-human EPO polyclonal antibody and glutaraldehyde–glass beads show the potential of this novel approach. The summarized findings are discussed in detail as a starting point for our ongoing investigations.