Immunoreagents based on polymer dispersions for immunochemical assays.

Immunoreagents based on polymer dispersions consisting of unimodal polyacrolein (PAL) microspheres with diameters in the range 0.3-2.0 microns have been prepared and evaluated by various immunoassay techniques such as immunoradiometric assay of ferritin and microtitre particle agglutination and immunofiltration dot assay of group-specific polysaccharide of S. pyogenes (A-PS) in comparison with conventional carriers and methods. The antibodies were covalently or indirectly bound to the PAL. The coupled antibodies to ferritin retained a high average affinity (Ka = 4.5 x 10(9) M-1). In comparison with microcrystalline cellulose-based immunosorbent, more than an order-of-magnitude lower amount of PAL-IgG was necessary for the analysis of ferritin. Use of PAL-IgG gave a higher sensitivity of assay with a detection limit of 0.7 x 10(-13) M l-1 and a wider concentration range of antigen detection (about four orders of magnitude) without manifestation of the high-dose hook effect. Particle agglutination assay of A-PS in microtitre plate was shown to be a simple, demonstrative and highly sensitive one-step analytical method with a detection limit of 0.05 ng A-PS/ml or 10(4) cells/ml. The sensitivity of immunofiltration assay using both enzyme and latex markers was shown to be approximately the same (50 ng A-PS/ml) and the duration of the assay was 3-5 min. No cross-reaction of latex conjugates with non-A Streptococcus cell lysates were observed.

[Simple immunoassays of pesticides based on the biotin-streptavidin system]. / Prostye immunokhimicheskie metody opredeleniya pestitsidov na osnove biotin-streptavidinovoi sistemy.

A simple method was developed for the preparation of a highly active streptavidin-peroxidase conjugate that enhances fourfold the sensitivity of bioassays. Using this conjugate, a quantitative assay of simazine and 2,4-dichlorophenoxyacetic acid (competitive ELISA) and a noninstrumental express method for simultaneous detection of these pesticides (dot-immunofiltration assay) were developed. The detection limit of the pesticides is 3-4 and 2 ng/ml and the duration of the assays is 1.5 h and 5 min for ELISA and dot-immunofiltration, respectively. The express method is easy and straightforward and enables the assay to be performed outside the laboratory.

[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.

Non-instrumental immunoassay based on coloured polyacrolein latex: application to group-specific polysaccharide of Streptococcus pyogenes.

Non-instrumental immunoassay methods 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, A-PS, of S.pyogenes (group A Streptococcus) and compared to the standard ELISA tests. The assay with the ability to detect the lowest concentration of antigen was MPA; as little as 0.05 ng A-PS/ml or 10(4) cells/ml could be detected in 1.5 h. In comparison to ELISA test the sensitivity of MPA was 10 times higher and the procedure of the assay was much more simple. The sensitivity of the immunofiltration assay using both enzyme and latex markers was shown to be the same (50 ng A-PS/ml) 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 easy to perform and require neither sophisticated equipment nor specially trained personal.