ABSTRACT
<p><b>OBJECTIVE</b>To prepare a rapid and sensitive diagnostic kit for detection of CA50 based on time-resolved fluoroimmunoassay.</p><p><b>METHODS</b>A sandwich-TRFIA diagmostic kit was developed using anti-CA50 monoclonal antibody and all parameters of the kit were evaluated.</p><p><b>RESULTS</b>The linear measurement range of the kit was (5 - 300) U/ml. The sensitivity was 0.2 U/ml. The intra- and inter-assay coefficients of variation were 4.3% - 8.2% and 7.7% - 11.2%, respectively. There was no cross-reaction with CEA, CA12-5, CA15-3 and AFP. The cross reactivity with CA19-9 was 0.7 U/ml. The correlation coefficient of detection results of 107 blood samples between this newly developed kit and commercially available CA50 RIA kit was 0.901.</p><p><b>CONCLUSION</b>This newly developed CA50-TRFIA kit is a valuable test tool for clinical application with even better sensitivity, specificity and accuracy.</p>