[Development of methods for rapid test of staphylococcal enterotoxin A in food].

Noninstrumental methods of qualitative rapid test for detection of staphylococcal enterotoxin A (SEA) in milk foods sample and brothof using immunochromatography (IC) and dot-assay has been developed. Monoclonal antibodies to SEA with colloidal gold forimmunochromatography; monoclonal antibodies to SEA with colloidal gold or biotinylated monoclonal antibodies and streptavidin-peroxidase conjugate for dot-assay were used to visualize the results. The detection limits, ng/mL: 10 (IC), 20 (dot-assay with antibody-colloidal gold), 10 (dot-assay with STR-HRP), 4 (ELISA). Time of assay, min: 25 (IC), 60 (dot-assay with antibody-colloidal gold), 70 (dot-assay with STR-HRPO, 150 (ELISA).

[Monoclonal antibodies labeled with colloidal gold for immunochromatographic express analysis of diphtheria toxin].

One-step rapid immunochromatographic method for detection of diphtheria toxin in different water samples (phosphate buffer, milk, human nasopharyngeal swab) with the conjugate of monoclonal antibodies labeled with colloidal gold was developed. The limit of visible detection of the diphtheria toxin is 10 ng/ml and 15 min time analysis. The use of silver sensitivity enhancement and scanning equipment decreased the detection limit to 1.25 ng/ml.

[Development of a rapid method for the detection of prostate-specific antigen by immunochromatography].

A single-step qualitative rapid test for the determination of prostate-specific antigen (PSA) in samples of human blood serum by immunochromatography using a complex of colloidal gold with monoclonal antibodies to PSA as the detection agent was developed. The determination limit for PSA in serum blood samples is 10 ng/ml; the analysis time, 15-25 min; the sensitivity of the method, 100%; and its specificity, 92.5%.

[Immunochromatographic analysis of 2,4-dichlorophenoxyacetic acid and simazine using monoclonal antibodies labelled with colloidal gold]. / Immunokhromatograficheskii analiz 2,4-dikhlorfenoksiukusnoi kisloty i simazina s ispol'zovaniem monoklonal'nykh antitel, mechennykh kolloidnym zolotom.

A method of the competitive immunochromatographic assay of the pesticides 2,4-D (2,4-dichlorophenoxyacetic acid) and simazine (2-chloro-4,6-bis(N-ethylamino)-1,2,5-triazine) in aqueous samples was developed. Monoclonal antibodies to these pesticides labeled with colloidal gold were used to visualize the results. The sensitivity of the 2,4-D and simazine assay is 12 ng/ml, and the time of analysis is 3-7 min. The method does not differ in sensitivity from the competitive EIA using conjugates of monoclonal antibodies to the pesticides with horseradish peroxidase; however, the time of the EIA is 1.5 h. The immunochromatographic method of the pesticide detection is available and simple and may be recommended for the development of assays of any other low-molecular compounds. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 2; see also http://www.maik.ru.

[A noninstrumental Immunoassay based on colloidal dyes]. / Neinstrumental'nyi immunoanaliz na osnove kolloidnykh krasitelei.

Detecting labels based on water dispersions of colloidal textile dyes were developed that are useful in various analytical and diagnostic test systems for a simple visual assessment of the assay. Colored water-insoluble particles of dyes were used for the sorptional immobilization of streptavidin on their surface. The resulting streptavidin-dye (STR-DYE) complexes possessed a high visualizing capacity and were used for the combined detection of pesticides (simazine and 2,4-dichlorophenoxyacetic acid) by noninstrumental immunoassay (DYE-comb-assay, competitive dot-immunoassay in the comb format). The detection limits and the duration of our DYE-comb-assay (4 ng/ml, 20-25 min), HRP-comb-assay (competitive dot-immunoassay in the comb format using the enzymic conjugate of STR with horseradish peroxidase) (16 ng/ml), and the traditional competitive ELISA (12-16 ng/ml, 1.5 h) were compared. This DYE-comb-assay is simple enough and can be used under field conditions.

[Determination of 2,4-dichlorophenoxyacetic acid using monoclonal antibodies and a biotin-streptavidin detection system]. / Opredelenie 2,4-dikhlorfenoksiukususno i kisloty s ispol'zovaniem monoklonal'nykh antitel i biotin-streptavidinovo i sistemy detektsii.

Simple methods to determine 2,4-dichlorophenoxyacetic acid (2,4-D) using biotinylated monoclonal antibodies in combination with a highly active streptavidin-peroxidase conjugate were developed on the basis of the immunofiltration dot assay and competitive enzyme immunoassay (EIA). The detection limit of 2,4-D acid for immunofiltration and EIA was 2-3 ng/ml, the total assay duration being 5 min and 1.5 h, respectively.

[Determination of free d-biotin--comparison of instrumental and non-instrumental methods of analysis]. / Opredelenie svobodnogo d-biotina--sravnenie instumental'nogo i neinstrumental'nogo metodov analiza.

Simple methods for determining free d-biotin were developed based on the latex agglutination reaction inhibition and competitive ELISA. Biotin-binding protein Str used as a biospecific marker was immobilized on the surface of colored polyacrolein latex particles or a nitrocellulose membrane. The sensitivity of both methods of the free d-biotin assay, which take 1.5 h, is 1.0-3.0 ng/ml.