Development of radioimmunoassay system for determination of human chorionic gonadotropin in human sera

The main objective of this study was the preparation and evaluation of the primary reagents for the liquid phase human chorionic gonadotropin-radioimmunoassay (HCG-RIA) kit. Polyclonal antibody is specific and valid; monoclonal antibodies are more specific. In HCG-RIA technique, polyclonal antibodies for beta HCG subunits with high binding and displacement % were used. 125I-HCG radioactive tracer was prepared with high yield 71.58 +/- 0.92%, purity 99.2 +/- 0.05%, and specific activity 170.42 +/- 1.65 mu Ci/mu g using chloramine T method, beta HCG polyclonal antisera and HCG standards in assay buffer matrix were locally prepared. In-house HCG-RIA was developed with high sensitivity 0.5 mIU/ml, specificity (99%), precision (CV% < 6.4 and < 8.3 for intra-and inter-assay, respectively), and accuracy (recovery range 96.4-104.3%) could be used for quantitative estimation of HCG in human sera for monitoring pregnancy and diagnosis of gestational trophoblastic diseases.

Automated summary

The main objective of this study was to prepare and evaluate primary reagents for the liquid phase human chorionic gonadotropin-radioimmunoassay (HCG-RIA) kit. Polyclonal antibodies were found to be specific and valid, while monoclonal antibodies were more specific. The developed in-house HCG-RIA method showed high sensitivity, specificity, precision, and accuracy, making it suitable for quantifying HCG in human sera for pregnancy monitoring and diagnosis of gestational trophoblastic diseases.