A homogeneous enzyme immunoassay with avidin-ligand conjugate as the enzyme-modulator

16 Methods for Detecting Microbial Pathogens in Food and Water

“…Unbound or weakly bound material must be removed between steps. Carrico et al, 1976Schroeder et al, 1976Burd et al, 1977Wei and Riebe, 1977Gibbons et al, 1980Ngo et al, 1981Bacquet and Twumasi, 1984Ngo and Lenhoff, 1981Voller et al, 1979Tijssen and Kurstak, 1981Friguet et al, 1983Engvall and Perlmann, 1971Van Weemen and Schuurs, Belanger et al, 1976Van Weemen et al, 1978 Homogeneous and heterogeneous EIAs can be subclassified into noncompetitive and competitive assays. In non-competitive EIAs, the antigen (microbe or substance of interest) within a sample is detected using complementary enzyme-labelled antibody.…”

Radioiodination and Other Labeling Techniques

“…These assays, which have been called enzyme-associated substance enzyme immunoassays (EASEIA) (SCHALL and TENOSO 1981), use tracers which are conjugates between a hapten and different substances able to influence the activity of an enzyme, including cofactors a), substrates (BURD et al 1977LI et al 1981;WORAH et al 1981), or inhibitors (FIN-LEY et al 1980Nao and LENOFF 1980;BACQUET and TWUMASI 1984;DONA 1985). These assays, which have been called enzyme-associated substance enzyme immunoassays (EASEIA) (SCHALL and TENOSO 1981), use tracers which are conjugates between a hapten and different substances able to influence the activity of an enzyme, including cofactors a), substrates (BURD et al 1977LI et al 1981;WORAH et al 1981), or inhibitors (FIN-LEY et al 1980Nao and LENOFF 1980;BACQUET and TWUMASI 1984;DONA 1985).…”

Pyruvate carboxylase as a model for oligosubstituted enzyme-ligand conjugates in homogeneous enzyme immunoassays

“…Since there is only one biotin molecule coupled per subunit, the enzyme can be considered as an oligosubstituted enzyme-ligand conjugate. Avidin is a slow binding inhibitor of pyruvate carboxylase (10) and this property has been used for the development of an enzyme modulator mediated immunoassay for 5,5-diphenylhydantoin (11). Since biological binders should have lower affinities for oligosubstituted conjugates than for multisubstituted ones, theoretically an improvement in detection limits could be achieved without any loss in selectivity.…”