[Enzyme immunoassay of ampicillin in milk].

An indirect immunoassay for quantitative determination of ampicillin (range, 10-1000 ng/ml) in buffer or milk has been developed. Polyclonal antibodies were obtained against ampicillin conjugated with bovine serum albumin; the conjugate was synthesized by direct condensation using carbodiimide. The antibodies were specific for ampicillin and exhibited low cross-reactivity to other penicillins (azlocillin, 17%; penicillin G, 10%; piperacillin, 5%; and carbenicillin, 4%). Matrix effects were minimized by combining the use of a casein-supplemented buffer (content of casein, 1%) with sample dilution. The threshold of ampicillin detection in milk (diluted tenfold) was equal to 5.0 ng/ml (which corresponded to 50 ng/ml of the original sample).

[Optimization of a method of solid-phase immunoenzyme analysis for determination of chloramphenicol in milk]. / Optimizatsiia metoda tverdofaznogo immunofermentnogo analiza dlia opredeleniia khloramfenikola v moloke.

The method of solid-phase enzyme linked immunosorbent assay (ELISA) for quantitative detection of chloramphenicol (CAP) in milk was developed. Peculiarities of the adsorption on the microtitre plates surface of CAP-ovalbumin conjugate were investigated. Different conditions of competition stage of the analysis were studied. Conditions providing CAP monitoring in human blood serum in the clinical range were optimized. Matrix effect on the assay results was studied. The specificity of the analytical system was investigated and the reagents stability was examined. The method developed permits CAP concentration to be determined in human blood serum, diluted 1/100, in the linear range from 0.1 to 100 ng/ml. The assay is characterized by high sensitivity (0.08 ng/ml) and good reproducibility (CV < 10.8%), assay time is about 3 hours. The correlation coefficient with HPLC is 0.977.

[Solid-phase immunoenzyme analysis of chloramphenicol in human blood serum]. / Tverdofaznyi immunofermentnyi analiz khloramfenikola v syvorotke krovi cheloveka.

The method of enzyme linked immunosorbent assay (ELISA) for quantitative detection of chloramphenicol (CAP) in human blood serum was developed. Peculiarities of the adsorption on the microtitre plates surface of CAP-ovalbumin conjugate were investigated. Different conditions of competition stage of the analysis were studied. Conditions providing CAP monitoring in human blood serum in the clinical range were optimized. Matrix effect on the assay results was studied. The specificity of the analytical system was investigated and the reagents stability was examined. The method developed permits CAP concentration to be determined in human blood serum, diluted 1/100, in the linear range from 10 to 1000 ng/ml. The assay is characterized by high sensitivity (1 ng/mL) and good reproducibility (CV < 12%), assay time is about 3 hours.

[Development of a solid-phase immunoenzyme analysis of gentamicin in human blood serum]. / Razrabotka tverdofaznogo immunofermentnogo analiza gentamitsina v syvorotke krovi cheloveka.

An enzyme immune test system was designed and optimized for quantitative assay of gentamicin in human sera. Immunospecific reagents i.e. gentamicin conjugates with ovalbumin (for sorption on polysterol plates) and with bovine serum albumin (immunogen) were prepared. Gentamicin specific antisera were isolated and tested. Conditions for the antigen sorption on polysterol plates were determined and optimized. Different regimes of the competition reaction were investigated and conditions for the antibiotic assay in human sera were determined. The assay specificity was studied and the stability of the test system was checked. An experimental lot of the reagent set was manufactured at the ZAO NPP Immunotech and the correlation tests with the use of the fluorescence polarization immunoassay were performed. The set is destined for the assay of 40 samples (in duplicate). The method sensitivity is 1 ng/ml of gentamicin. The range of the detectable concentration is 1 to 32 ng/ml of gentamicin in 1000-fold diluted sera. The assay time is not more than 3 hours. The variation coefficient of the results does not exceed 12 per cent. The shelf-life of the set is 0.5 years when stored at a temperature of 2 to 8 degrees C.

[Polarization fluoroimmunoassay of propazine in reversed micelles of aerosol OT in octane]. / Poliarizatsionnyi fluoroimmunoanaliz propazina v obrashchennykh mitsellakh aérozolia OT v oktane.

The interaction between fluorescein-labeled propazine and antibodies against this hapten was studied in the reversed micelles of Aerosol OT in n-octane by a polarization fluoroassay. The effect of the hydration degree of micelles W0 (W0=[H2O]/[Surf]), which determines their size and surfactant concentration, on the binding of the antigen with antibodies was studied. A high hydration degree of the reversed micelles (W0 = 15-30) and low concentration of the surfactant (less than 50 microM) are optimal for binding. The binding efficacy depends upon the structure of the fluorescein-labeled hapten, particularly upon the length of the bridge binding fluorescein with propazine. It was shown that the polarization fluoroimmunoassay of propazine may be carried out in a reversed micellar system in nonpolar organic solvent (octane) with a detection limit of about 100 nM (20 microns/l). This is an order of magnitude higher than that achievable upon analysis in aqueous medium. The proposed polarization fluoroimmunoassay in a reversed micellar system makes it possible to detect haptens that are poorly soluble in water directly in organic extracts, e.g. in chloroform solutions.

[The problem of selecting the structure of a labelled antigen in developing a fluorescence polarization immunoassay for atrazine]. / Problema vybora struktury mechenogo antigena pri razrabotke poliarizatsionnogo fluoroimmunoanaliza atrazina.

Influence of labelled antigens structure on the sensitivity of the polarization fluoroimmunoassay of atrazine was studied. It is shown that the highest sensitivity is provided by the use of the heterologous labelled reagent with the shortest chemical bridge between the antigen and fluorescent label.

[Polarization fluorescence immunoanalysis of herbicides of the S-1,3,5-triazine class]. / Poliarizatsionnyi fliuorestsentnyi immunoanaliz na gerbitsidy klassa sim-1,3,5-triazinov.

Polarization fluoroimmunoassay for s-triazine herbicides was developed. The sensitive of assay is higher with using shortest chemical "bridge" length between the molecule of antigen and fluorescent label. The detection limit of atrazine in 50 microL sample was 6 ng/ml. The total time required for an assay of 10 samples was 6 ng/ml. The total time required for an assay of 10 samples is approximately 7 min. The method may be used for environmental monitoring of s-triazine herbicides in water samples.