Using the molecular imprinting approach, we have shown that polyacrylamide-based artificial antibodies against human and bovine hemoglobin have a very high selectivity, as revealed by the free-zone electrophoresis in a revolving capillary. By the same technique we have previously synthesized gel antibodies not only against proteins but also against viruses and bacteria. The synthesis is thus universal, i.e., it has the great advantage of not requiring a modification - or only a slight one - for each particular antigen. The combination synthesis of artificial gel antibodies and electrophoretic analysis reveals small discrepancies in shape and chemical composition not only of proteins, as shown here and in paper la, but also of viruses and bacteria, to be illustrated in papers II and III in this series. Upon rehydration, the freeze-dried gel antibodies, selective for human hemoglobin, regain their selectivity. The gel antibodies can repeatedly be used following the removal of the antigen (protein in this study) from the complex gel antibody/antigen by an SDS washing or an enzymatic degradation.