Rabbit antibody production tests

The disaccharide was synthesized as its -nltrophenyl derivative and subsequently, as described above, covalently linked to BSA to yield the glycoconjugate AR-BSA (18). Immunized rabbits responded with antibody production with specificity for the saccharide hapten, as demonstrated in ELISA studies (19). When tested in immunofluorescence, the AR-BSA antiserum proved to be of the same excellent specificity for the identification of Salmonella serogroup C2-C3 bacteria as had been shown previously for the other dldeoxyhexose-contalnlng dlsaccharlde haptens (Figure 1) (19). 

Methylisocytosine (LVIII, superacyl) has been reported to stimulate antibody production in rabbits to an extent greater than with a vaccine alone [354]. It also markedly reduced the development of pulmonary adenoma at 100 mg/kg per day for 10, 25 or 50 days s.c. or p.o. to mice, following a single i.p. injection of urethan. 5-Hydroxy-6-methylisocytosine had the same effect [19]. In tests on the effect of pyrimidines on reticuloendothelial functions in mice, the absorptive capacity of this system increased with 5-(hydroxymethyl)uracil or with 6-methylisocytosine. The effect was most pronounced when superimposed on cortisone inhibition [355]. When administered subcutaneously to mice, 6-methylisocytosine increased the inhibitory effect of thio-TEPA on the growth of Ehrlich tumours in mice. It is believed that this pyrimidine prevents the development of metastases [356]. 

Data in Table 1 indicate that these particular LPS tested do not cross-react with antibodies to cotton dust. This suggests that these particular endotoxins are not associated with the antigenic materials found in cotton dust or bract or that their concentrations were not high enough to be a factor in the production of active serum in rabbits. 

Development of immunoassays for residue analysis of small molecules has been well documented in the literature (8-9. 141 and by the articles in this volume. Recently, Dreher and Podratzki (101 reported the development of an immunoassay for endosulfan and its metabolites using a rabbit polyclonal antiserum. This assay however, did not readily detect other related cyclodiene insecticides. We report here the development of a monoclonal antibody that detectes all nine of the cyclodiene insecticides tested plus toxaphene, and the incorporation of this antibody to an immunoassay for detecting these compounds in meat, fish, and dairy products at, or below, the tolerance levels. 

In this paper preparation of antigens and production as well as testing of antibodies raised against different hemicelluloses will be described and examples of their application in chemical mapping of pulp fibres will be presented. Hemicelluloses from different sources were subjected to enzymatic hydrolysis and the oligosaccharides formed were separated and coupled to a carrier protein prior to immunisation of rabbits. 

The absence of detectable response to MBS A in the mouse is not surprising, since Plescia and Braun (1967) have reported that this protein is not antigenic in this rodent. Use of the technique of Farr (1958) allowed a comparison of the production of antibodies against poly I poly C in mice and rabbits immunized with the same preparation of poly I poly C — MBS A (Fourcade et al., manuscript in preparation). The average percentage of poly I poly C bound by the immune sera was 14 (xg/ml antiserum in mice and 21 fig/ml antiserum in rabbits. The hamster displays the same responses to carrier protein as the mouse, and the antibodies induced react with poly I poly C but not with MBSA, when tested by immunodiffusion. 

Many of the early ELISA methods devised for botulism neurotoxin detection, like most of the in vitro tests,suffered from a lack of specificity, due to impurities in the antigen preparation used to produce the antitoxins. More purified toxins are now available for the production of better quality antitoxins. The most sensitive ELISA protocols use an indirect assay sometimes referred to as the sandwich assay. In the basic procedure, a specific antitoxin is first adsorbed to the surface of the wells of a plastic plate. The toxin added to the wells is then bound by these antibodies and detected with a second antitoxin which is conjugated to an enzyme or other labeling molecule. The amount of label is measured by supplying the enzyme substrate, which is converted to a colored product that is measured colorimetrically. Some ELISA protocols use a polyclonal antitoxin on one side of the sandwich and a monoclonal on the other side. Other assays use the same antibody for both sides but label the antibody the second time it is used. A modification of the sandwich assay is the double sandwich ELISA, which employs a third antibody that is conjugated to an enzyme and is directed against the second antitoxin it is an anti-antibody such as rabbit anti-horse IgG. The steps in a typical application of this assay for botulism toxin are shown in Figure 2. 

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