| abstract |
A reagent is disclosed for determining the concentration of a ligand in blood serum. The reagent includes a protenaceous, three-dimensional, serum-insoluble complex which is readily collected by centrifugation, the complex comprising non-specific immunoglobulins, anti-ligand immunoglobulins, immunoglobulins which are antibodies to the previously mentioned immunoglobulins and which are complexed therewith, and a labeled ligand complexed with the anti-ligand immunoglobulins. The reagent is particularly useful in competitive binding analyses such as radioimmunoassays. |