Using microtitration method, the relationship between Phenoloxidase activity and the resistance of the diamondback moth Plutella xylostella (Linnaeus) to the novel insecticide butane-fipronil was determined in vitro. After selection of the tenth-generation by butane-fipronil, the resistance of the fourth instar larvae was increased 83.80-fold as compared to the susceptible strain. Phenoloxidase...

Soluble antigen prepared from pseudorabies virus-infected embryonic pig kidney cells was used to demonstrate the presence of pseudorabies virus antibodies in sera taken from naturally and experimentally infected swine. Antibody could be detected by agar-gel immunodiffusion as early as 14 days postexposure and was demonstrable at least 3 months after experimental infection (the longest period te...

We describe a procedure for the simultaneous immunofluorometric assay of lutropin and follitropin in human serum, based on the use of monoclonal antibodies and of the fluorescent lanthanides Eu3+ and Tb3+. The alpha-chain-specific antibody was used as a common capture antibody on the surfaces of microtitration strips. The anti-beta-follitropin antibody was labeled with Tb3+, the anti-beta-lutro...

We developed a direct competitive-type immunoassay for progesterone in serum that combines the advantages of the biotin-streptavidin system with the antibody-immunobilization approach. We synthesized biotinylated progesterone derivatives of five different proteins and, after initial evaluation of the conjugates, selected biotinylated bovine IgG-progesterone as the most suitable tracer. Progeste...

Conditions were assessed which would permit more rapid recognition of bacterial growth than has been previously reported using tetrazolium salts. Microtitration trays were used. 2-(p-Iodophenyl)-3(p-nitrophenyl)-5-phenyltetrazolium chloride is rapidly reduced by respiring cells in tissue homogenates but is more toxic than other tetrazoliums when added to growing bacterial cultures. Phenazine me...

We describe a simple hybridization assay performed in microtitration wells with use of DNA probes labeled with three different lanthanide chelates for detection of seven mutations that cause cystic fibrosis. The assay is based on DNA amplification of four fragments containing the mutations (delta F508, G1717-->A, G542X, R553X, 3905 insertion T, W1282X, and N1303K) by PCR, followed by hybridizat...

A rapid, semiautomated microdilution method was developed for measuring the activity of potential antimalarial drugs against cultured intraerythrocytic asexual forms of the human malaria parasite Plasmodium falciparum. Microtitration plates were used to prepare serial dilutions of the compounds to be tested. Parasites, obtained from continuous stock cultures, were subcultured in these plates fo...

In this rapid, simple enzyme immunoassay for carcinoembryonic antigen (CEA) in serum the "sandwich" system is used. The CEA is first extracted from the serum into acetate buffer by heating at 70 degrees C, then incubated in a polyvinyl microtitration plate previously coated with anti-CEA. The bound CEA is then reacted with anti-CEA conjugated to horseradish peroxidase and the activity of the pe...

We have performed a one-step all-in-one dual-label dry reagent time-resolved fluorometric assay measuring free and total prostate-specific antigen (PSA). All assay-specific components were predried in an ordinary microtitration well, including the Eu and Tb chelate-labeled monoclonal antibodies for the recognition of free and total PSA, respectively. Only the sample and assay buffer needed to b...