For point-of-care testing of the illegal fortification of repaglinide (Rep) in natural dietary supplements, a competitive chemiluminescent immunoassay (CLIA) was established, using a horseradish peroxidase (HRP)-luminol-H2O2 system for signal amplification. Polyclonal antibodies for Rep were produced via immunization technique. Following optimization of the enzyme reaction time and concentrations of antibody and coating antigen, the method showed a limit of quantification (LOQ) of 1.0 ng/mL in PBS and limit of detection (LOD) of 8.3 ng/mL in serum and 6.0 ng/mL in blank tablets. When applied in natural dietary supplements, the method provided results consistent with those from HPLC, suggesting that the proposed method could be used for rapid screening of Rep in natural dietary supplements and detecting Rep in serum after administration.
A rapid and homogenous fluorescence polarization immunoassay (FPIA) for diethyl phthalate is reported. Two haptens and three immunogens for diethyl phthalate were synthesized to generate polyclonal antibodies and fluorescein isothiocyanate labeled diethyl phthalate was prepared as the tracer. The antibodies, methanol concentration, and incubation time were optimized. The cross-reactivities of the optimized antibodies to other phthalate esters were characterized. The antibody shows excellent sensitivity with a limit of detection of 6.0 ng mL À1 and a half-inhibition concentration of diethyl phthalate of 40.4 ng mL À1 . The immunoassay had a linear dynamic range from 10 to 200 ng mL À1 . The mean coefficient of variation was lower than 11.3% for intra-assay and lower than 14.6% for inter-assay measurements. The limit of detection was 1.46 ng mL À1 in bottled drinking water, 0.34 µg mL À1 in juice, and 50.0 µg g À1 in pharmaceutical capsules. The recovery was from 85.9 to 114.9%, and the coefficients of variation were 4.3 to 17.0%. The developed immunoassay provided good sensitivity, specificity, accuracy, and may serve as an alternative for diethyl phthalate determination for field screening of food, pharmaceuticals, and environmental materials.
Polyclonal antibodies for anticancer drug methotrexate (MTX) were originally produced, and a chemiluminescence immunoassay was developed for plasma MTX determination.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.