title: An immuno-enzymatic assay of cortisol using E. coli beta-galactosidase as label.
abstract: An enzyme-assay of cortisol was established by using E. coli beta-galactosidase as a marker. The number of cortisol residues per molecule of enzyme and the method of separation of free from antibody-bound enzyme proved to be critical factors for the assessment of the assay. A sensitivity ranging from 100 to 150 pg of cortisol per tube has been achieved. A comparsion with other methods, i.e. competitive protein binding assay, radioimmunoassay and fluorimetry, is reported.
mesh_terms: D000818:Animals; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D004926:Escherichia coli / Q000201:enzymology*; D005470:Fluorometry; D005696:Galactosidases / Q000378:metabolism*; D006854:Hydrocortisone / Q000032:analysis*; D007118:Immunoassay / Q000379:methods; D011817:Rabbits; D011863:Radioimmunoassay
chemical_list: D005696:Galactosidases; D006854:Hydrocortisone