摘要:

A competitive enzyme immunoassay of histamine in foodstuffs has been developed using a monoclonal antibody against a histamine‐benzoquinone adduct. In this assay, histamine present in food samples was treated with 1,4‐benzoquinone to form histamine‐benzoquinone by a simple and quick reaction and a histamine‐benzoquinone‐horse‐radish peroxidase conjugate was used as the labelled hapten. The apparent association constant (Ka) of the antibody used was 3.6 ×106l/mol and Gibbs’ energy of the immune complex formation has been estimated to find the optimal incubation time of the assay. The method enabled determination of histamine in fish, cheese, wine and beer at a concentration as low as 7 ng/ml with an accuracy of ± 15%. The recovery of the immunoassay was 88.9–114%. Cross‐reactivities of histidine, tyramine, tryptamine and its derivatives were lower than 0.001% and did not affect the assay.

ISSN:0954-0105    

DOI:10.1080/09540109209354754

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A sensitive competitive solid‐phase enzyme immunoassay for the detection oftert‐butylic beta‐agonist drugs was developed. An antiserum was raised in rabbits against the diazo‐conjugate of clenbuterol and the human serum albumin. In the assay, the anticlenbuterol antibody was incubated with the salbutamol‐enzyme conjugate and unlabelled standard or samples in microtitre wells precoated with affinity‐purified antirabbit IgG. The absolute detection limit for clenbuterol and mabuterol was 0.3 ng/ml (15 pg/well) and 50% relative binding at 1.0 ng/ml (50 pg/well). The absolute detection limits for salbutamol and terbutaline were 0.9 and 1.3 ng/ml, respectively. The cross‐reactivity of iso‐propylic parent compounds was quite low (<1%). Urine and sera were tested without any extraction step. Sample blanks (96 urine and 76 sera from five different sources) showed low matrix effect, suggesting a limit of decision for bovine urine of 0.6 ng/ml clenbuterol equivalent. Mean recoveries of clenbuterol in spiked urine and serum samples ranged from 90 to 120% (mean recovery 96%). Comparative analysis by gas chromatography/mass spectrometry showed that false negative results do not occur. The assay is simple, rapid, sensitive, multiresidual, reliable and cost‐effective. The test is adaptable to high sample throughput laboratories as well as field test for rapid screening of a few samples in slaughterhouses.

ISSN:0954-0105    

DOI:10.1080/09540109209354755

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Polyclonal antibodies against aflatoxins were obtained from egg yolks of laying hens immunized with either aflatoxin B1(AFB1) or aflatoxin M1(AFM1) conjugated to bovine serum albumin (BSA). An indirect enzyme‐linked immunosorbent assay (ELISA) involving the use of AFB1‐BSA or AFM1‐BSA conjugate and anti‐chicken IgG‐horseradish peroxidase (HRP) conjugate, was developed for monitoring antibody titers and aflatoxin analysis. Production of the antibody in hens started as early as 10 days after immunization and reached a maximum in 20 days. Competitive indirect ELISA revealed that the antibodies were most specific for AFB1. They were cross‐reactive with other aflatoxins in the following order: B1(100%)>G1(22–28%)>B2(6–16%)>M1(3–9%)>G2(1–4%). Anti‐AFM1‐BSA antibodies showed a similar pattern of cross‐reaction to the anti‐AFB1‐BSA antibodies when AFB1‐BSA was coated to the ELISA plate. The specificity of anti‐AFM1‐BSA to AFM1was demonstrated when AFM1‐BSA was coated to the ELISA plate. Cross‐reactivity with different aflatoxins was in the following order: M1(531%)>B1(100%)>G2(41%)>G1(19%)>B2(3%). The sensitivity for AFB1analysis in the indirect ELISA was 0.05–5 ng AFB1/assay.

ISSN:0954-0105    

DOI:10.1080/09540109209354756

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A double sandwich enzyme‐linked immunosorbent assay (ELISA) procedure for the quantification of IgG in bovine milk was developed for detecting the concentration of IgG in various homogenized HTST, UHT, evaporated and raw milk samples as well as skim milk powder. ELISA results were consistently lower than radial immunodiffusion (RID) values for the same sample, suggesting interference by an unknown constituent in the milk matrix. This difficulty was overcome by using a reference milk, quantified previously for IgG by RID. A significant linear relationship (y=2.03x‐0.034, r=0.891, n= 150, p<0.001) was obtained for IgG content in unknown raw milk samples determined by ELISA using serial dilutions of the reference milk (y) or commercial IgG (x) to construct standard curves. The slope of the regression line could be used as a correction factor. Alternatively, IgG in unknown samples could be directly quantified from absorbance values of reference milk serial dilutions assayed on the same ELISA plate. Using this procedure, homogenized, HTST pasteurized milk contained from 65 to 79% of the IgG found in raw milk. Skim milk powder also retained a major portion of IgG, while evaporated and UHT pasteurized milk were virtually devoid of IgG.

ISSN:0954-0105    

DOI:10.1080/09540109209354757

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Enzyme‐linked immunosorbent assays (ELISAs) were developed for the detection of antibodies toMycoplasma synoviae, Pasteurella multocida,reovirus, infectious bursal disease virus (IBDV), infectious bronchitis virus (IBV), and egg‐drop syndrome (EDS). Purified antigenic preparations derived from the various pathogens were used to coat microtitre plates and their shelf‐life was determined. There was no significant difference in ELISA absorbance values determined on paired antigen coated microtitre plates stored at —20°C and at room temperature, desiccated, for 63 days. When stored at 4°C, desiccated, antigen coated plates had a shelf‐life of up to 390 days. A linear relationship was established between the two sets of values with correlation coefficients ranging from 0.796 to 0.993.

ISSN:0954-0105    

DOI:10.1080/09540109209354758

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Enzyme‐linked immunosorbent assays (ELISAs) were developed for the detection of antibodies toMycoplasma synoviae,infectious bronchitis virus (IBV)Pasteurella multocida,infectious bursal disease virus (IBDV), reovirus, egg‐drop syndrome (EDS) and reticuloendotheliosis virus (REV). Purified antigenic preparations derived from the various pathogens were used to coat microtitre plates. A non‐specific factor in some serum samples bound to many of the antigen‐coated plates. Such non‐specific binding was shown to be related to the age of the chicken and to immunization schedules.

ISSN:0954-0105    

DOI:10.1080/09540109209354759

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Development and Application of Immunoassays for Food Analysis

ISSN:0954-0105    

DOI:10.1080/09540109209354760

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0954-0105    

DOI:10.1080/09540109209354753

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor