[Products of spontaneous conjugation of aflatoxins with bovine serum albumin: immunochemical properties]. / Immunokhimicheskie svoistva spontannykh kon"iugatov aflatoksinov s bych'im syvorotochnym al'buminom.

Products of spontaneous conjugation of aflatoxins B1, G1, and G2 with bovine serum albumin (BSA) were shown to interact with antibodies against aflatoxins. Solid-phase BSA conjugates inhibited the binding of aflatoxins by anti-aflatoxin antibodies. Antisera against BSA-B1, BSA-G1, and BSA-G2 were obtained and their specificity, determined. The mechanisms of spontaneous binding of aflatoxins by proteins are discussed.

[Specific features of albumin interactions with hemiacetals of aflatoxins and sterigmatocystin]. / Osobennosti vzaimodeistviia gemiatsetalei aflatoksinov i sterigmatotsistina s albuminom.

Aflatoxin B2a (AB2a), aflatoxin G2a (AG2a), and hemiacetal of sterigmatocystin have been shown to form immunoreactive conjugates with albumin. The conjugates were formed following incubation of solution mixtures at room temperature for 1 h, as demonstrated by spectrophotometry and enzyme immunoassay. Anti-AB2a antibodies reacted with AB2a, aflatoxin B1, and aflatoxin AB2 (100, 8.8, and 5.9%, respectively); a similar result was obtained for anti-AG2a antibodies reacting with AG2a, aflatoxin G1, and aflatoxin AG@2 (100, 2.5, and < 1.0%, respectively). Binding of anti-AB2a and anti-AG2a antibodies to solid-phase conjugates of AB2a or AG2a exhibited similar analytical characteristics.

[Comparative characteristics of immunoreagents based on aflatoxin B1 hemiacetals and sterigmatocystine]. / Sravnitel'naia kharakteristika immunoreagentov na osnove gemiatsetalei aflatoksina B1 i sterimatotsistina.

Aflatoxin B1 and sterigmatocystine hemiacetal derivatives were synthesized, and their conjugation to albumins and gelatin and also spectral and immunochemthe specificity and analytical properties of the antibodies produced by immunization with conjugated antigens. The possible mechanism of hemiacetal interaction with proteins is discussed. Based on immune reagents to sterigmatocystine hemiacetal, a test system was developed for determination of sterigmatocystine at the sensitivity of 0.1 ng/ml.

[Production and analytical properties of antibodies with high specificity to zearalenone]. / Poluchenie i analiticheskie svoistva antitel s vysokoi spetsifichnost'iu k zearalenonu.

The time course of production, specificity, and analytical potential of anti-zearalenone polyclonal rabbit antibody synthesized by formaldehyde condensation and conjugated to bovine serum albumin were investigated. The relative cross-reactivities with natural analogues were: zearalenone, 100%; alpha-zearalenol, 0.15%; and beta-zearalenol, < 0.02%. With synthetic analogues: zearalanone, 31.7% and alpha-zearalanol, 0.12%. An enzyme immunoassay for zearalenone with a sensitivity of 0.1 ng/ml was developed on the basis of these antibodies and solid-phase conjugates homologous to the immunogen in the method of synthesis.

[Group-specific antibodies against zearalenone and its metabolites and synthetic analogs]. / Poluchenie antitel s gruppovoi spetsifichnost'iu k zearalenonu, ego matabolitam i sinteticheskim analogam.

Formation kinetics, specificity, and analytical potential of polyclonal antibodies raised in rabbits against BSA conjugates of carboxymethyloxime-zearalanone (CMO-ZAN) and carboxymethyloxime-zearalenone (CMO-ZEN). Preparation of the conjugates involved conversion of CMO-ZAN and CMO-ZEN into activated esters and carbodiimide condensation. Two versions of a group-specific enzyme immunoassay (for zearalenone/alpha-zearalenone and zearalanol/alpha-zearalanol) based on heterologous combination of solid-phase antigens are described (sensitivity, 0.01 ng/ml).

[Preparation of antibodies to roridin A and their applications]. / Poluchenie antitel k roridinu A i ikh primenenie.

Polyclonal rabbit antibodies against a conjugate synthesized through condensing BSA and disubstituted roridin A hemisuccinate allowed roridin A to be determined in solutions at a sensitivity of 0.2 ng/ml. The cross-reactivity of structural analogues--roridin A, verrucarin, and verrucarol--amounted to 100, 2.5, and 0.03%, respectively. The data showed that these antibodies determine roridin A in an indirect heterogeneous enzyme immunoassay in cereal straw samples at a sensitivity of 20 micrograms/kg.

[Preparation of conjugated antigens based on zearalenone carboxymethyloxime and their use in immunoenzyme analysis]. / Poluchenie kon''iugirovannykh antigenov na osnove karboksimetiloksima zearalenona i ikh primenenie v immunofermentnom analize.

Zearalenone-6'-carboxymethyloxime was synthesized, and its conjugates with albumins and gelatin were prepared. Polyclonal rabbit antibodies against the conjugate with bovine serum albumin were shown to be highly specific to zearalenone and to have a lower cross-reactivity toward its structural analogues (alpha-zearalenol--28%, beta-zearalenol--6%, zearalanone--12%, and alpha-zearalanol--5%). The sensitivity of enzyme immunoassay using gelatin-based immobilized conjugates for determination of zearalenone in solutions was 1 ng/ml, and this allowed us to determine this substance in feed at a threshold concentration of 200 micrograms/kg.

[Ochratoxin A: study of grain contamination]. / Okhratoksin A: issledovanie kontaminatsii zerna.

Ochratoxin A was quantitatively monitored in grain extracts by indirect solid-phase enzyme immunoassay with the use of an immobilized conjugate of the toxin with gelatin and polyclonal rabbit antibodies raised against the ochratoxin A-BSA conjugate. This monitoring found that 1.7 to 18.5% of the samples were contaminated with the toxin at a concentration of 25.9-291.7 micrograms/kg. An analysis of forage grain found ochratoxin A at concentrations of 440-3250 micrograms/kg.

[Immunoenzyme test system for detection of aflatoxin B1]. / Immunofermentnaia test-sistema opredeleniia aflatoksina B1.

Indirect enzyme immunoassay based on immobilized conjugate of aflatoxin B1 carboxymethyloxime with bovine serum albumin and polyclonal rabbit antibodies allows determining aflatoxin B1 with a low relative cross-reactivity against aflatoxin B2, G1, G2, M1, B2a and G2a and sterigmatocystin (15.5, 15.5, 1.7, 1.0, 0.03, 0.03 and 0.01%, respectively) with a sensitivity of 0.04 ng per well or 4.0 ng per ml organic solvent.

[Immunoenzyme assay for detection of T-2 toxin in contaminated grain]. / Immunofermentnyi metod opredeleniia T-2 toksina v kontaminirovannom zerne.

Based on indirect solid-phase competitive enzyme immunoassay, a method for determination of T-2 toxin in grain was designed. Determination errors were measured on samples of contaminated grain. The method makes allows determination of the toxin levels ranging from 30 to 1000 ng/g.

[Application of competitive immunoenzyme assay for analysis of group B fumonisins]. / Primenenie tverdofaznogo konkurentnogo immunofermentnogo analiza dlia opredeleniia fumonizinov gruppy B.

A varriant of competitive ELISA, making it possible to detect fumonisin B1 (up to 0.4 ng/well) was developed, based on the use of specific polyclonal antibodies obtained by immunization of rabbits with a horseradish peroxidase conjugate of fumonisin B1. The minimum concentration of fumonisin B in water-acetonitrile extracts of corn grain, dry corn products, and feeds, detected by the ELISA version developed is 0.2 mg/kg.