Preparation and identification of dual-label time-resolved fluoroimmunoassay for simultaneous detection of alpha fetoprotein and carcinoembryonic antigen

Objective To establish and identify dual-label time-resolved fluoroimmunoassay(TRFIA) for simultaneously detecting alpha fetoprotein(AFP)and carcinoembryonic antigen(CEA) in serum.Methods The mixture monoclonal antibody(McAb) of anti-AFP(E014) and anti-CEA(3E6) were co-coated in the 96 microtitration wells.The anti-AFP McAb(E010) was labeled with Sm3+-chelates and anti-CEA McAb(S001) was labeled with Eu3+-chelates.The dual-label time-resolved fluoroimmunoassay were developed by one-step double-antibody sandwich.Results The assay sensitivity for AFP was 0.3 U/ml and the measurable ranges of was 0.3～800 U/ml,and the recovery rate was 99.8%.The intra-and inter-assay coefficient of variation(CV) were 2.1%～5.8% and 4.1%～8.7%,respectively.The assay sensitivity for CEA was 0.2 U/ml and the measurable ranges of was 0.2～400 U/ml.The recovery rate was 100.3%.The intra-and inter-assay CV were 2.4%～5.6% and 4.8%～9.8%,respectively.The correlation coefficient of 100 blood samples detection results between home-made dual-label TRFIA and commercially available single-label DELFIA kit(PerKin Elmer) were 0.99 for AFP and 0.98 for CEA,respectively.Conclusions The home-made AFP/CEA TRFIA kit is valuable for clinical application with very satisfactory sensitivity,specificity,and accuracy.It may be used to replace the single-label reagents for diagnosis of primary hepatic carcinoma or large-scale general survey and screen of liver disease.