[Immunochromatographic and latex-agglutination systems for diphtheria toxin detection].

The use of two monoclonal antibody types specific to different epitopes of diphtheria toxin systems have been developed to reveal diphtheria corynebacteria toxigenicity rapidly based on immunochromatographic and latex-agglutination detection of the diphtheria toxin. The methods have been tested on a sample of 36 clinical isolates. The possibility of significant detection of the toxigenic properties of the Corynebacterium strain, grown for 1 day, has been demonstrated. The developed methods allow for the detection of diphtheria toxin in concentrations of 3-4 ng/ml. The developed test systems are a perspective tool for diphtheria diagnostics because of significant time shortening as compared to traditional microbiological methods.

[Development of monoclonal latex diagnostic kit for diphtheria toxin and toxoid detection].

Latex diagnostic kit with high specificity and sensitivity of diphtheria toxin and toxoid detection has been developed on the basis of protective monoclonal antibodies to diphtheria toxin and polyacrolein microspheres. Diagnostic kit was stable during 1 year of shelf-life (time of the study).

[Turbidimetric study of latex agglutination in 2,4-dichlorophenoxyacetic acid analysis]. / Turbidimetricheskie issledovaniia reaktsii lateksnoi aggliutinatsii pri opredelenii 2,4-dikhlorofenoksiuksusnoi kisloty.

By the example of 2,4-dichlorophenoxyacetic acid (2,4-D) assay by the inhibition of latex agglutination, new synthetic polymer microspheres for the conjugation with antibodies to 2,4-D and agglutinators based on ovalbumin and polyacrylamide were developed and characterized. The effect of various parameters (the concentration of reagents, the type and the degree of modification of the microsphere surface, and the nature of the carrier in the composition of the agglutinator) on the rate of agglutination and the maximal optical absorption observed during the reaction were studied by turbidimetry. The optimal parameters were found for the assay of 2,4-D by the inhibition of latex agglutination with turbidimetric registration of the results.

[Molecular design of polymeric materials for biotechnology and medicine]. / Molekuliarnoe konstruirovanie polimernykh materialov dlia biotekhnologii i meditsiny.

This review describes new polymer materials for biomedical applications developed in the Polymers for Biology Laboratory of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences. These include composite rigid sorbents for biochromatography, polymer dispersions for immunoassay, polymer hydrogels for immobilization of enzymes and cells, and polymer ultra thin films as biomembrane models and materials for biosensors. Some general and specific properties of these new materials and models as well as examples of their applications are discussed.

[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.

[Use of a latex-agglutination test for determining anti-measles antibody titer]. / Ispol'zovanie testa lateks-aggliutinatsii dlia opredeleniia titrov protivokorevykh antitel.

A new diagnostic agent for microtitration of antimeasles antibodies, making use of polyacrolein microspheres conjugated with purified measles virus has been developed. Parallel titration of blood sera of children and adults in latex agglutination test and in routine test (hemagglutination inhibition, passive hemagglutination, immunofluorescent tests) demonstrated a sufficient specificity of the new test, sensitivity compatible to that of hemagglutination inhibition, and correlation of the results of all tests.

[Polyacrolein latex as a solid phase carrier for radioimmunoassay. Comparison with microcrystalline cellulose and polystyrene test tube surface]. / Poliakroleinovyi lateks v kachestve tverdofaznogo nositelia dlia immunoradiometricheskogo analiza. Sravnenie s mikrokristallicheskoi tselliulozoi i poverkhnost'iu polistirol'nykh probirok.

The immunosorbent obtained through a covalent immobilization of antibodies on a polyacrolein latex was studied in comparison with the sorbents based on microcrystalline cellulose and with the surface of polystyrene test tubes in a two-center radioimmunoassay for ferritin. It was shown that the polyacrolein latex provides a covalent binding of up to 75 mg protein per g dry polymer with an immobilization efficiency of 50-70% and a high effective association constant of immobilized antibodies (Ka = 4.5 x 10(9) M-1). The same parameters for the sorbent based on microcrystalline cellulose were 33 mg/g, 25-35%, and 4.3 x 10(8) M-1, respectively. In the radioimmunoassay for ferritin, the immunosorbents based on polyacrolein latex and cellulose ensured a nearly the same analytical sensitivity at the level of (0.7-0.9) x 10(-13) M ferritin and pointed to the possibility of eliminating the "hook-effect". Compared to the immunosorbent based on polystyrene test tubes, the advantages of the polyacrolein latex are the decrease in the minimum detectable concentration (increase in analytical sensitivity), the extension of the dynamical range of analysis, and the absence of the "hook-effect".

[A microtitration variant of the latex agglutination reaction in the diagnosis of leprosy]. / Mikrotitratsionnyi variant reaktsii lateks-aggliutinatsii v diagnostike lepry.

The authors describe the preparation of antigenic diagnostic agent based on stained polyacrolein latex particles conjugated with beta-(3-aminopropyl) 3, 6-dimethylglucopiranoside (DMG), a synthetic analog of PSL = 1 from M. leprae (L-PMG), and its use in the microtitration variant of latex agglutination for the serological diagnosis of lepra. The test was performed in polystyrene plates. A total of 45 blood sera of patients with lepra, 34 sera of subjects who had contacts with leper patients, and 148 control samples were tested. The level of antibodies to DMG was found to be related to the bacterial loading of the patient. If the patients with regressive are seropositive, it means that persistent forms of M.leprae are present in their organs and tissues. "Nonleprous" sera did not react with L-PMG. The microtitration latex agglutination test proved to be highly specific (93.3%) and sufficiently sensitive (87.3%). It is rapid and simple, the results may be assessed visually; this recommends the method for seroepidemiologic screening in the regions where lepra cases are recorded.

[Noninstrumental immunoanalysis based on dyed polyacrolein latexes. Determination of a group-specific polysaccharide from Streptococcus pyogenes]. / Neinstrumental'nyi immunoanaliz na osnove okrashennykh poliakroleinovykh lateksov. Opredelenie gruppospetsificheskogo polisakharida Streptococcus pyogenes.

Non-instrumental immunoassays based on immunofiltration and microtiter particle agglutination (MPA) techniques have been developed using coloured polyacrolein latex. These methods have been applied to the quantification of the group-specific polysaccharide (PS) of S. pyogenes (group A streptococcus) and compared with standard ELISA tests. The most efficient method was MPA; as little as 0.05 ng A-PS/ml could be detected in 1.5 h. In comparison with ELISA test, the sensitivity of MPA was 10 times higher and the procedure was much simpler. The sensitivity of immunofiltration assay using both enzyme and latex conjugates was shown to be the same (50 ng/ml A-PS) and the duration of the assay 3-5 min. No cross-reactions of latex conjugates with non A streptococcus cell lysates have been observed. The developed methods are rapid, robust, easy to perform, don't need any sophisticated equipment and specially trained staff.

[The determination of measles antibody titers in the latex agglutination reaction]. / Opredelenie titrov protivokorevykh antitel v reaktsii lateks-aggliutinatsii.

A new latex agglutination test (LAT) for detection of antibodies to measles virus in blood sera was developed. The latex diagnosticum consists of polymeric microspheres of national make carrying on their surface covalently bound measles virus antigen. The data on the specificity and sensitivity of the test are presented, and the results of titrations of blood sera from schoolchildren by traditional HI test and LAT are compared. LAT was shown to be highly sensitive, much simpler than the available methods for detection of measles antibodies and more economic, and therefore may be recommended for mass surveys.

[A method for the passive agglutination of polymer dispersions for the diagnosis of legionellosis]. / Metod passivnoi aggliutinatsii polimernykh dispersii dlia diagnostiki legionelleza.

The method of synthetizing dispersions of gelatin-modified polyacrolein microspheres 1.5-2.5 micrograms in diameter, used as a solid-phase carrier for the preparation of immunodispersion diagnostica, has been developed. The possibility of using immunodispersion diagnosticum in the passive agglutination test with hyperimmune rabbit sera has been demonstrated. High activity and specificity of immunodispersion diagnosticum, combining methodological simplicity and rapidity characteristic of agglutination, has been shown.

[The preparation of an IgG diagnostic agent based on stained polyacrolein latexes for use in the latex agglutination reaction]. / Prigotovlenie IgG-diagnostikuma na osnove okrashennykh poliakroleinovykh lateksov dlia primeneniia v reaktsii lateksnoi aggliutinatsii.

IgG diagnosticum for measuring the concentration of 131I-labeled IgG antibodies to enteric antigen beta 1MA by the latex agglutination inhibition (LAI) test has been prepared on the basis of polyacrolein latexes. A method for the titration of anti-IgG antibodies with the use of the above diagnosticum has been developed, based on the late, agglutination (LA) test. The optimum conditions for the microtitration variant of the LA and LAI tests have been defined. High sensitivity, specificity and simplicity of analysis with the use of latex IgG diagnosticum have been demonstrated. The newly developed methods have been successfully used in laboratory trials of a new diagnostic radiopharmaceuticals for the assay of 131I-labeled antibodies in this preparation and for the detection of side effects of immunization on the recipients.

[Hybridization analysis of nucleic acids using stained latex]. / Gibridizatsionnyi analiz nukleinovykh kislot s ispol'zovaniem okrashennykh lateksov.

Method of the latex hybridization analysis has been developed: after hybridization of NA-target with biotinylated probe visualization of hybrids was carried out using latex particles, containing fluorescent dye pyronin G and coated with streptavidin. Due to encapsulation of the fluorescent dye in polymer particles sensitivity of the analysis was increased by several orders of magnitude in comparison with methods, using fluorescently labelled probes. Possessing a number of advantages, the method yields to none of any other methods of NA hybridization analysis in sensitivity.

[Experimental visualization of human colon cancer using 131I-antibodies to intestinal beta 1 MA antigen]. / Vizualizatsiia kartsinom tolstoi kishki cheloveka s pomoshch'iu 131I-antitel k kishechnomu antigenu beta 1 MA v éksperimente.

131I-antibodies to human beta 1 colonic antigen was administered i.v. to nude mice with transplanted human colon carcinoma. Injections were followed by mouse whole-body investigation with the help of gamma-camera and scanner. The distribution of radioactivity in murine tissues was investigated with a gamma-counter. Sharp images of tumor were obtained with the help of the gamma-camera and scanner. The results of visualization were in accord with radioimmunometric data. A conclusion was made of effective visualization of human colon carcinoma transplanted to nude mice using iodinated antibodies to specific beta 1 MA epithelial colonic antigen.