摘要:

Polyclonal anti‐hypoxanthine antisera have been raised in rabbits and sheep. Purine and pyrimidine bases are poor immunogens, and strategies for affinity purification of antisera were developed in order to concentrate, for the first time, appropriate antibodies against an individual base.

ISSN:0954-0105    

DOI:10.1080/09540109209354762

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We have synthesized a novel dioxin immunogen, 2‐adipamide‐7, 8‐dichlorodibenzodioxin‐BSA, with a view to generating antibodies suitable for use in an immunoaffinity column. The specificity of antisera raised in rabbits to this conjugate was assessed in a competitive enzyme‐linked immunosorbent assay which was sensitive to 1 ng 2,3,7,8‐tetrachlorodibenzodioxin well‐1. Cross‐reactivity studies indicated that the antibodies were more sensitive to this congener than to the more highly chlorinated structures which are considered less toxic. 3,3’,4,4,‐Tetrachlorobiphenyl was unable—at any concentration—to displace antibody from the solid phase. We consider such specificity would be eminently suitable for immunoaffinity columns in the clean‐up and concentration of samples prior to dioxin determination by gas chromatography/mass spectrometry.

ISSN:0954-0105    

DOI:10.1080/09540109209354763

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A sensitive, specific, quantitative enzyme‐linked immunosorbent assay (ELISA) has been developed that can be used to determine the extent of mycelial growth of a sporulating thermophilic fungus, Humicola lanuginosa on the surface of rice grains. The assay employs a monoclonal antibody EC6, developed in a previous study, which does not recognize spores of the fungus. Using antigen‐coated wells, a direct linear relationship was established between dilutions of extracts from freeze‐dried mycelium (0.5 to 3 μg/ml) and absorbance values but to eliminate day‐to‐day variations it was found to be necessary to run a dilution series, prepared from stock freeze‐dried mycelium, with every test sample. The ELISA method was compared with conventional quantitative methods. Estimates of total mycelial length in freeze‐dried material by ELISA were found to be in the same order of magnitude as those determined by ergosterol and a theoretical calculation. The ELISA method also compared favourably with direct linear measurements (by photomicrography) of live mycelium present in aliquots from homogenates of a 1 cm2plug taken from a plate but estimates of the latter by the dilution plate count method were much lower. In assays with inoculated rice grains, the quantitative ELISA method proved more sensitive than either the ergosterol method or direct plating of surface‐sterilized grains. The ELISA method also has the advantage of being highly specific and quick to conduct.

ISSN:0954-0105    

DOI:10.1080/09540109209354764

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An immunoassay has been developed which facilitates discrimination between canned whole sardine (Sardina pilchardus Walbaum) and other fish species (Pacific pilchard, mackerel, herring, sild and anchovy) that may be substituted for it in the canned product. The non‐competitive indirect ELISA utilizes an antiserum raised against a crude water‐soluble extract of canned sardine. Appropriate antiserum specificity was ensured by using extracts of those fish with which cross‐reactivity was undesirable, to achieve post‐production ‘blocking’ of unwanted cross reactions. This assay will be of value in upholding EC and UK law on the composition and labelling requirements of canned sardine products and provides a basis for the development of a rapid test format.

ISSN:0954-0105    

DOI:10.1080/09540109209354765

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An immunoassay has been developed which facilitates discrimination between white fish, such as coley, and crustacean tailmeat, such as scampi. Preliminary studies with this non‐competitive indirect ELISA clearly demonstrate the feasibility of using immunochemical tests for detecting adulteration of high value crustacean tailmeat products with lower value white fish.

ISSN:0954-0105    

DOI:10.1080/09540109209354766

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Allergies to several plant foods, i.e. apples, nuts, stone fruits, celery and spices, are highly associated with pollen allergies. The observed crossreactivities are due to structural similarities between food and pollen allergens. Using horseradish peroxidase (HRP) as the marker enzyme we have further developed and optimized a sensitive and specific immunoblotting procedure for the detection of human IgE antibodies specific to food and pollen proteins separated by SDS‐PAGE and immobilized on nitrocellulose blots. Our optimization studies involved four colour substrates and six buffer systems. The best results were obtained when 0.3% Tween 20 and no protein was used for membrane blocking, whereas blocking with proteins yielded high backgrounds. Immuno‐ detection amplification was accomplished by the following incubation steps: (a) sample (human serum); (b) secondary antibody; (c) biotinylated tertiary antibody; and (d) streptavidin‐HRP. Staining was performed with 3,3',5,5'‐tetramethylbenzidine which is an Ames test‐negative, alternative substrate for HRP. The quality of several commercially available anti‐IgE antibodies was examined. For some of these reagents very high non‐specific binding to food and pollen proteins occurred. The application of our method to apple and birch pollen allergen characterization is described. Results of IgE‐ and IgG‐immunoblotting and immuno‐detection of allergens following two‐dimensional‐ electrophoresis, as well as cross‐reactivity studies by means of immunoblot inhibition, are presented.

ISSN:0954-0105    

DOI:10.1080/09540109209354767

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0954-0105    

DOI:10.1080/09540109209354761

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor