Detection of brucella specific protein-A reactive antibodies in buffaloes by dot-enzyme-linked immunosorbent assay

1988 ◽  
Vol 122 (7) ◽  
pp. 162-163 ◽  
Author(s):  
P. Chand ◽  
H. Batra ◽  
J. Sadana
1994 ◽  
Vol 57 (3) ◽  
pp. 184-189 ◽  
Author(s):  
TSUNG C. CHANG ◽  
SU H. HUANG

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the rapid detection of Staphylococcus aureus in foods. The assay was based on the detection of protein A which is a specific protein secreted by S. aureus. Following a 24-h incubation in a staphylococcal selective broth containing mannitol as the carbon source, the culture supematant was added to the microtiter plate coated with anti-protein A immunoglobulin G (IgG). After incubation, peroxidase-labeled anti-protein A IgG was used to produce the signal of antigen-antibody reaction. The sensitivity of the assay for protein A was 0.1 ng/ml. For 37 strains of S. aureus studied, all produced protein A, and the amount (13-1,100 ng/ml) of protein A secreted by different strains varied to a large degree. For another 57 strains (including 19 Staphylococcus spp.) of bacteria tested, two strains (5. capilis subsp. capitis CCRC 12161 and S. lentus CCRC 12926) produced very low amounts of protein A (0.6-1 ng/ml) after 24-h incubation. Staphylococcus aureus was detected by the ELISA in all of six samples of precooked foods naturally contaminated with the bacterium. Twenty-two processed foods artificially inoculated with S. aureus at levels of < 2 CFU/g and 10 to 20 CFU/g, respectively, were all positive by the ELISA. As compared to the conventional culture methods which take 5 to 6 days to complete, the ELISA can detect low numbers of S. aureus in processed foods with a total analytical time of only 28 h.


1986 ◽  
Vol 13 (2) ◽  
pp. 64-67 ◽  
Author(s):  
J. L. Sherwood ◽  
H. A. Melouk

Abstract Western blotting was used to detect infections of peanut cv. Tamnut 74 with peanut mottle virus (PMV) and/or peanut stripe virus (PStV). Leaf samples were ground in electrophoresis sample buffer and heated for 5 min at 95 C prior to electrophoresis in 12% polyacrylamide gels. After electrophoresis, proteins were transferred to nitrocellulose sheets at 100V for 45 min. Western blots were performed by first blocking unbound sites on the nitrocellulose with 5% non-fat dry milk in Tris-buffered saline (TBS), pH 7.4 for 30 min, followed by incubation in a 1/200 dilution of PMV and/or PStV antiserum in TBS (the latter antiserum provided by J. W. Demski, U. of GA) for 45 min. This was followed by incubation in protein-A-peroxidase (2 μg/mL in TBS) for 45 min, followed by 4-chloro-1-napthol plus hydrogen peroxide in TBS. As little as 25 ng of either purified PMV or PStV was detected. This was similar to the limits of detection fo the double sandwich enzyme linked immunosorbent assay (ELISA). Because of the difference in migration of the coat proteins of PMV and PStV, both viruses may be detected in plants infected with PMV and PStV. This assay can be performed in approximately 6 h when mini-gels are used for the initial electrophoretic seperation and does not require the antiserum to be fractionated or bound to an enzyme as is the case with ELISA.


1987 ◽  
Vol 33 (2) ◽  
pp. 98-103 ◽  
Author(s):  
G. Lazarovits ◽  
D. Zutra ◽  
M. Bar-Joseph

The usefulness of enzyme-linked immunosorbent assay on nitrocellulose membranes (dot–ELISA) for diagnosis and identification of plant pathogenic bacteria was tested. Five pathovars of Xanthomonas campestris and two antisera, one produced against pv. vesicatoria and the other against pv. translucens, were used in a model system. A 10-min incubation of the bacterial cells, dot blotted on membranes, in diluted sera, followed by either alkaline phosphatase conjugated protein A or goat antirabbit globulin, resulted in a specific reaction between the homologous serum and bacteria. Populations of 1000–2000 cfu per spot (ca. 0.3 cm2) could be detected with these reagents. The streptavidin–biotinylated peroxidase complex produced a definitive reaction with as few as 800 cfu, but cross-reactions became evident at the higher cell concentrations among all five pathovars in tests with both antisera. Cell-free extracts, obtained by centrifugation of boiled bacteria, reacted similarly to live cells. Unrelated bacteria did not react with either antiserum. Extracts of lesions from tomato and pepper leaves infected with X. campestris pv. vesicatoria reacted positively with the antiserum produced against this pathovar but not that produced with pv. translucens. Samples of supernatants from boiled lesions reacted with similar intensity as those from homogenized tissues.


2006 ◽  
Vol 3 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Xu Wen-Tao ◽  
Huang Kun-Lun ◽  
Deng Ai-Ke ◽  
Luo Yun-Bo

AbstractWe have developed and applied an immunoassay method to detect genetically modified (GM) rape containing phosphinothricin acetyltransferase (PAT). The purified PAT was identified by Western blotting and enzymic activity analysis. The polyclonal antibody against purified PAT protein was obtained and purified by both a saturated ammonium sulphate method and protein A-Sepharose 4B. The sensitivity and cross-reactivity of the polyclonal antibody has been demonstrated in an enzyme-linked immunosorbent assay (ELISA). The result of the ELISA for antiserum sensitivity was about 2×10−5mg/ml and the cross-reactivity determined experimentally showed a high degree of specificity for the antiserum used, because values were all less than 0.1%. Detection of transgenic plants was evaluated using two transgenic rape lines (MS1/RF1 and MS8/RF3) which could be easily distinguished by ELISA.


2000 ◽  
Vol 38 (11) ◽  
pp. 4160-4166 ◽  
Author(s):  
Fang Ting Liang ◽  
Richard H. Jacobson ◽  
Reinhard K. Straubinger ◽  
Amy Grooters ◽  
Mario T. Philipp

Sera collected from dogs experimentally infected withBorrelia burgdorferi by tick inoculation were analyzed for an antibody response to each of the six invariable regions (IRs; i.e., IR1 to IR6) of VlsE, the variable surface antigen of B. burgdorferi. Six synthetic peptides (C1 to C6), which reproduced the six IR sequences were used as peptide-based, enzyme-linked immunosorbent assay (ELISA) antigens. Two IRs, IR2 and IR6, were found to be immunodominant. Studies with serially collected serum samples from experimentally infected dogs revealed that the antibody response to IR6 appears earlier and is stronger than that to IR2. Thus, the IR6 sequence alone appeared to be sufficient for serodiagnosis. When C6 alone was used as antigen, the peptide-based ELISA was positive in 7 of 23 dogs (30%) as early as 3 weeks postinfection. All dogs (n = 33) became strongly positive 1 or 2 weeks later, and this response persisted for the entire study, which lasted for 69 weeks. Of 55 sera submitted by veterinarians from dogs suspected of having Lyme disease, 19 were also positive by the C6 ELISA, compared to 20 positives detected by immunoblot analysis using cultured B. burgdorferi lysates as antigen. The sensitivity of using C2 and C6 together for detecting specific antibody in both experimentally infected and clinically diagnosed dogs was not better than sensitivity with C6 alone, confirming that C6 suffices as a diagnostic probe. Moreover, the C6 ELISA yielded 100% specificity with serum samples collected from 70 healthy dogs, 14 dogs with infections other than B. burgdorferi, and 15 animals vaccinated with either outer surface protein A, whole-spirochete vaccines, or the common puppy-vaccines. Therefore, this C6 ELISA was both sensitive and specific for the serodiagnosis of canine Lyme disease and could be used with vaccinated dogs.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Chalisa Jaturapaktrarak ◽  
Penpan Payattikul ◽  
Tassanee Lohnoo ◽  
Yothin Kumsang ◽  
Aree Laikul ◽  
...  

2012 ◽  
Vol 19 (12) ◽  
pp. 1977-1979 ◽  
Author(s):  
Lucyna Holec-Gąsior ◽  
Bartłomiej Ferra ◽  
Dorota Drapała

ABSTRACTThis study describes aToxoplasma gondiiIgG enzyme-linked immunosorbent assay based on a new chimeric antigen containing three immunodominant regions from the MIC1, MAG1, and SAG1 proteins of the parasite and shows that this test is useful for diagnostic purposes and may replace the lysed and whole-cell antigens.


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