title: A highly sensitive microtitre plate enzyme immunoassay for oestradiol-17 beta.
abstract: A specific and sensitive solid-phase microtitre plate enzyme-linked immunosorbent assay for oestradiol-17 beta (E2) is described. After coating with an IgG anti-E2 fraction, we used E2-6-carboxymethyl-oxime-beta-galactosidase in a competitive binding assay and revealed the bound activity with a fluorogenic substrate. Two methods for the competitive binding assay were tested: (1) a classical one (method A) defined as a 'two-step competition' because the E2 sample was first incubated alone, and then E2-beta-galactosidase conjugate was added; (2) and a new one (method B) also performed in two steps but in which the E2 sample was evaporated to dryness. The detection limit of method A was 100 pg/ml (9 pg/well). Method B was more sensitive since 1 pg/ml (0.3 pg/well) was statistically different from 0 pg/ml. Specificity was equivalent with both methods while precision was better in B. Thus, this new method may be able to measure very low levels of oestradiol-17 beta in, for example, the blood of domestic mammals.
authors.affiliation: Station de Physiologie de la Reproduction, INRA, Nouzilly, France.
authors.forename: M C
authors.initials: MC
authors.lastname: Maurel
authors.forename: H
authors.initials: H
authors.lastname: Labrousse
authors.forename: M
authors.initials: M
authors.lastname: Terqui
authors.forename: S
authors.initials: S
authors.lastname: Avrameas
mesh_terms: D001667:Binding, Competitive; D003429:Cross Reactions; D004306:Dose-Response Relationship, Immunologic; D004958:Estradiol / Q000032:analysis*; D007124:Immunoenzyme Techniques; D008832:Microchemistry; D011863:Radioimmunoassay
chemical_list: D004958:Estradiol