Detection of anti-estradiol antibodies and of 17beta-estradiol by means of a 17beta-estradiol-bacteriophage T4 conjugate. Dependence of the haptenated phage reaction on several physical parameters

Immunoassay for honey bee cytochrome c in single animals with cytochrome c-coated bacteriophages: a sensitive tool for the study of caste formation in the honey bee, Apis mellifera

The development of a sensitive viroimmunoassay for honey bee cytochrome c and its usage for early detection of caste differentiation is described. Pure honey bee cytochrome c was isolated from workers and used to produce antibodies in rabbits. Bacteriophage T4 was chemically modified by covalent attachment of honey bee cytochrome c using tolylene-2,4-diisocyanate as a cross-linking agent. The immunospecific inactivation of this bacteriophage-cytochrome c conjugate by anti-cytochrome c antibodies can be inhibited by free cytochrome c. In quantitative determinations, 50% inhibition is reproducibly achieved at a concentration of 6 ng/ml (5 pmol/ml) and as little as 0.3 ng/ml (0.25 pmol/ml) could be detected by this system. Cytochrome c concentrations were measured in individual animals and substantial differences corresponding larval stages of worker and queen bees are reported.

Inactivation of hapten-modified bacteriophage by antibody: increased sensitivity of the assay in media containing polyethylene glycol

Inactivation of dinitrophenylated bacteriophage T4 by porcine and rabbit anti-dinitrophenyl (DNP) antibodies was studied by the complex inactivation methods. The inactivation titers increased 20-30 times when polyethylene glycol, mol. wt. 6000, was added to the incubation media. Consequently, the detection of dinitrophenylated serum albumin with the modified bacteriophage could be carried out with higher sensitivity upon addition of polyethylene glycol.