Development of light initiated chemiluminescent immunoassay for Carbohydrate antigen CA19-9

Objective:To develop a light initiated chemiluminescent immunoassay for detection of Carbohydrate antigen CA19-9(CA19-9) in human serum.Methods: Two monoclonal antibodies with different epitopes to CA19-9 were selected.One was coated with luminescent microspheres,and the other was biotinylated.The CA19-9 concentration in human sera was determined by double antibody sandwich light initiated chemiluminescent immunoassay,and the results were compared with Roche Reagent(electro-chemiluminescent immunoassay).Results: The detection range of the assay was 0 U/ml~500 U/ml,when the concentrations of the luminescent microspheres and the biotinylated antibody were 25 mg/ml and 16.17 mg/ml respectively.The sensitivity was 0.27 U/ml,and the recovery rate was 101.26%.The within-run and between-run coefficients of variation(CV)were 1.67%~4.35% and 1.12%~3.25% respectively.The cross reaction rates of the assay with carcino-embryonic antigen(CEA),carbohydrate antigen 12-5(CA12-5),carbohydrate antigen 15-3(CA15-3) were low.The stability of the detection method was good.The coincidence rate with the electro-chemiluminescent immunoassay was highly significant(conformity=98.8%,γ=0.991).Conclusion: The light initiated chemiluminescent immunoassay for human CA19-9 detection have high sensitivity,precision and accuracy.The coincidence rate with Roche kits is high,so this assay can be applied for clinical determination.