How can antibodies be used to detect human chorionic gonadotropin?

Immunoassay: A technique known as the immunoassay, first developed by Berson and Yalow in the late '50's and early '60's, and for which they won the Nobel prize in 1977, uses hCG-specific antibodies to quantifiably identify the hCG, then a secondary antibody with a quantifiable marker (color, radioactivity, etc) to identify the hCG/hCG antibody complexes. It remains a very important means of testing in endocri