identification of a substance (especially a protein) by its action as an antigen

a physiological test to determine whether a woman is pregnant

immunoassay of a substance that has been radioactively labeled

pregnancy test that involves injecting some of the woman's urine into an unmated female rabbit and later examining the ovaries of the rabbit; presence of corpora lutea indicates that the woman is pregnant

a quantitative or qualitative test of a substance (especially an ore or a drug) to determine its components; frequently used to test for the presence or concentration of infectious agents or antibodies etc.