摘要:

A novel coloured latex test for the detection ofSalmonellain naturally contaminated foods is described. The test consists of two reagents which are mixtures of red, blue and green latex suspensions; each colour of latex is sensitized with specific antibodies to different groups ofSalmonella.In the presence of an individual group ofSalmonellaorganisms, the latex sensitized with the antibody specific to that grouping will agglutinate to produce a crescent of single colour latex particles and a change of background colour. Seven trial centres, within the UK, evaluated the performance of the coloured latex test for the detection ofSalmonellain natural and artificially contaminated foods. The results obtained by the trial laboratories are presented and show that it is possible to combine the coloured latex test with traditional or electrial methods to give detection and/or confirmation ofSalmonellaat least 24 hours in advance of conventional cultural methods.

ISSN:0954-0105    

DOI:10.1080/09540108909354669

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

During the past decade several immunoassays for detection of staphylococcal enterotoxins (SE) have been developed. Of the assays developed the enzyme‐linked immunosorbent assay (ELISA) has been proven to be the most appropriate method for detecting small quantities of SE in foods. In the course of time, however, it has become clear that in using the ELISA equivocal results may be obtained. Therefore, control experiments have to be introduced to check for both false negative and false positive results. In this study the use of anti‐idiotypic monoclonal antibody to control false positive ELISA‐reactions is described. Using a monoclonal antibody as coating antibody, it has been shown that the anti‐idiotypic monoclonal antibody and its F(ab')2fragment prevents binding of SE. Addition of anti‐idiotypic Flab')2fragments to test samples changed a positive reaction into a negative only if SE is present. Samples with positive reactions without SE remained positive. Therefore F(ab')2fragments of anti‐idiotypic monoclonal antibodies can be used to recognize false positive reactions.

ISSN:0954-0105    

DOI:10.1080/09540108909354670

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A two site enzyme‐linked immunosorbent assay for wheat gliadins has been developed. Polyclonal antibodies from chicken eggs were used as the capture agent adsorbed to the surface of the microtitration plate. Murine monoclonal antibodies bound to captured gliadin were detected by addition of enzyme‐labelled, species‐specific antibodies. The assay was developed for the purposes of screening monoclonal antibodies specific for conformational epitopes on gliadins. The properties of a panel of 6 anti‐gliadin antibodies in the assay were assessed and compared to properties exhibited under conditions where conformational epitopes were less likely to be present. Three of the monoclonal antibodies appeared to be specific for conformational epitopes.

ISSN:0954-0105    

DOI:10.1080/09540108909354671

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The technology of the preparation of monoclonal antibodies to purified ciguatoxin (CTX) and okadaic acid (OA) are presented in this report. The cross‐reactivity of monoclonal antibody to CTX (MAb‐CTX) with purified OA (16%), ionomycin (2%) and ionophore A23187 (9%) are shown. Monoclonal antibody to OA (MAb‐OA) reacts with purified CTX (30%), while reaction with ionomycin (0.2%) and A23187 (3%) are minimal under the conditions examined. Thus, the cross‐reactivity of CTX and OA is demonstrated and in agreement with structural analysis. Furthermore, these MAbs are of importance in the detection of marine toxins in contaminated fishes.

ISSN:0954-0105    

DOI:10.1080/09540108909354672

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A direct ELISA for the thiocarbamate herbicide molinate was used to study distribution and dissipation of the compound in a treated rice field. No sample preparation other than buffering and dilution was required for the analysis of field water samples. Analyses were performed in 96‐well microplates and required less than 0–5 man‐hour per sample (three dilutions per sample, four replicate wells per dilution). Spiked samples and selected field samples were split for analysis by ELISA and gas chromatography. Two control samples of 92 and 93 ppb (after dilution) had between run coefficients of variation of 13.8 and 13.9% for 37 ELISA runs. A nested ANOVA analysis revealed that the largest source of error for the ELISA was due to within replicate variability, partly attributable to interwell variability of the 96‐well plates. Practical aspects of reducing assay error and handling ELISA data are discussed. Quality control data showed that reliability of the direct ELISA is comparable to the gas chromatography method for molinate. ELISA data from field samples showed concentration differences among sites in the same check which coincided with differences in water flow. The half‐life of molinate in the field, as determined by ELISA, was comparable to the value determined by chromatography.

ISSN:0954-0105    

DOI:10.1080/09540108909354673

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

An enzyme‐linked immunosorbent assay (ELISA) has been developed for the specific detection ofPseudomonas syringaepv.phaseolicola,the agent of haloblight disease of beans. Using as an immunogen a preparation of a surface polysaccharide known to be characteristic of the organism because of involvement in the mechanism of pathogenicity, antisera have been raised which show no cross‐reaction with other pathovers ofP. syringaetested, and which recognized all strains of pv. phaseolicola tested. This degree of specificity has not previously been reported. The assay limit of detection is 2×104cells ml−1.A positive result was obtained when artifically inoculated bean flour was analysed by ELISA. The antiserum was also used for detection of the organism by fluorescence microscopy. The method is considerably faster than alternative methodology.

ISSN:0954-0105    

DOI:10.1080/09540108909354674

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

To check the concentrations of hen egg lysozyme in foodstuffs, added as a bacteriostatic agent, immunoassays based on different labels have been developed. The following detection limits (defined as non‐specific binding increased by three standard deviations) were achieved using antibody labelled with either peroxidase125I or a biotin‐streptavidin system: 0–8; 0–75 and 0–13 ng/ml, respectively. Only the most sensitive lysozyme immunoassay was likely to be suitable for application to analysis of cheese because matrix interference effects mean that sample extracts need to be diluted prior to assay.

ISSN:0954-0105    

DOI:10.1080/09540108909354675

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0954-0105    

DOI:10.1080/09540108909354668

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor