Radioimmunossay of hormones and metabolites in blood serum and plasma

Hormones or metabolites which are capable of producing antibodies can be detected and precisely quantitated by this method. Antibodies, to various hormones or metabolites whose assay is desired, are adsorbed onto commercially available imitation or cultured pearls. These pearls coated with antibody are contacted with a buffered reaction mixture containing blood serum or plasma specimen and respective radioactive antigen. The entire reaction is allowed to proceed for a time sufficient to form antigen (radioactive or non-radioactive)-antibody complex. These complexes on the pearls are washed and the total amount of radioactivity emanating from the complex is measured. This is indicative of the extent of binding of radioactive antigen and provides an indirect correlation of the amount of non-radioactive antigen present in the serum or plasma sample