Application of BODIPY-labeled erythromycin for macrolide detection by a fluorescence polarization immunoassay

Immune methods of analysis are widely used in laboratories in various fields of medicine, including enzyme immunoassay (ELISA), polarization fluorescence immunoassay (FPIA) and immunochromatographic analysis. The FPIA method allows for high specificity and sensitivity of low-molecular-weight analytes in a homogeneous medium without separation and has the ability to automate the analysis system, high accuracy, label stability, and speed and simplicity of analysis. In this work, a fluorescently labeled tracer for the determination of erythromycin with new BODIPY dye was obtained. A pair of immunoreagents (tracers and antibodies) for detecting these antibiotics were selected and characterized. The conditions for conducting FPIA were optimized, calibration curves were obtained, and the analytical characteristics of the FPIA were determined: detection limit, range of detectable concentrations, sensitivity and cross-reactivity. Using the developed FPIA methods for determining antibiotics most commonly used in veterinary medicine, water samples collected from reservoirs in Moscow and the Moscow region were tested. Thus, in this work, the FPIA method for determining erythromycin with a detection limit of 1.6 ng/ml was developed, the advantages of using the new fluorescent label BODIPY were shown, the accuracy of the method was verified by an introduced-found test, and real water samples were tested.