Evaluation of α-fetoprotein (AFP) in human serum by chemiluminescence enzyme immunoassay with magnetic particles and coated tubes as solid phases

In this work, the monoclonal antibodies (McAbs) to α-fetoprotein (AFP) were immobilized on two different solid phases, i.e., magnetic particles (MP) and coated tubes (CT). Based on this, a MP based chemiluminescence enzyme immunoassay (MP-CLEIA) and a CT based CLEIA (CT-CLEIA) were proposed for the evaluation of AFP in human serum and their analytical merits were studied and compared. By detailed discussion of several performance variants, including the concentration of immobilized McAb, dilution ratio of horseradish peroxidase (HRP) labeled McAb (HRP-McAb), total assay time, substrate volume, chemiluminescent kinetics, and hook effect concentration, the advantages of MP-CLEIA became conspicuously apparent. Moreover, in the presence of MP, the catalytic activity of labeled enzyme was kept to high extent and the stability of immunoreagents was satisfied. Finally, 59 human serum samples were detected by the MP-CLEIA and a good correlation was obtained when comparing the results with that from a commercial electrochemiluminescence immunoassay kit.