Protein A-based antibody immobilization onto polymeric microdevices for enhanced sensitivity of enzyme-linked immunosorbent assay

2009 ◽  
Vol 102 (3) ◽  
pp. 891-901 ◽  
Author(s):  
Yuan Yuan ◽  
Hongyan He ◽  
L. James Lee
Keyword(s):  
Immunosorbent Assay ◽  
Protein A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Immobilization ◽  
Enhanced Sensitivity

A Comparison of an Enzyme Linked Immunosorbent Assay (ELISA) and Western Blotting for Detection of Peanut Mottle Virus and Peanut Stripe Virus1

1986 ◽  
Vol 13 (2) ◽  
pp. 64-67 ◽  
Author(s):  
J. L. Sherwood ◽  
H. A. Melouk
Keyword(s):  
Western Blotting ◽  
Immunosorbent Assay ◽  
Protein A ◽  
Mottle Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Coat Proteins ◽  
Western Blots ◽  
Peanut Stripe Virus ◽  
Dry Milk ◽  
The Difference

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.

Enzyme-linked immunosorbent assay on nitrocellulose membranes (dot–ELISA) in the serodiagnosis of plant pathogenic bacteria

1987 ◽  
Vol 33 (2) ◽  
pp. 98-103 ◽  
Author(s):  
G. Lazarovits ◽  
D. Zutra ◽  
M. Bar-Joseph
Keyword(s):  
Immunosorbent Assay ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Protein A ◽  
Live Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Cells ◽  
Plant Pathogenic Bacteria ◽  
Pepper Leaves ◽  
Dot Elisa

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.

Enzyme linked immunosorbent assay for PAT protein detection in genetically modified rape

2006 ◽  
Vol 3 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Xu Wen-Tao ◽  
Huang Kun-Lun ◽  
Deng Ai-Ke ◽  
Luo Yun-Bo
Keyword(s):  
Immunosorbent Assay ◽  
Polyclonal Antibody ◽  
Genetically Modified ◽  
Protein A ◽  
Protein Detection ◽  
Cross Reactivity ◽  
Enzymic Activity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sepharose 4B ◽  
Pat Protein

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.

scholarly journals Characterization of a Borrelia burgdorferi VlsE Invariable Region Useful in Canine Lyme Disease Serodiagnosis by Enzyme-Linked Immunosorbent Assay

2000 ◽  
Vol 38 (11) ◽  
pp. 4160-4166 ◽  
Author(s):  
Fang Ting Liang ◽  
Richard H. Jacobson ◽  
Reinhard K. Straubinger ◽  
Amy Grooters ◽  
Mario T. Philipp
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Antibody Response ◽  
Immunosorbent Assay ◽  
Protein A ◽  
Immunoblot Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Entire Study ◽  
Variable Surface

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.

scholarly journals Enzyme-Linked Immunosorbent Assay with Conserved Immunoreactive Glycoproteins gp36 and gp19 Has Enhanced Sensitivity and Provides Species-Specific Immunodiagnosis of Ehrlichia canis Infection

2006 ◽  
Vol 14 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Ana Maria Cárdenas ◽  
C. Kuyler Doyle ◽  
Xiaofeng Zhang ◽  
Kimberly Nethery ◽  
Richard E. Corstvet ◽  
...  
Keyword(s):  
Acute Phase ◽  
Immunosorbent Assay ◽  
Fluorescent Antibody ◽  
Etiologic Agent ◽  
Ehrlichia Canis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Recombinant Glycoprotein ◽  
Enhanced Sensitivity ◽  
Canine Monocytic Ehrlichiosis ◽  
Species Specific

ABSTRACT Ehrlichia canis is the primary etiologic agent of canine monocytic ehrlichiosis, a globally distributed and potentially fatal disease of dogs. We previously reported on the identification of two conserved major immunoreactive antigens, gp36 and gp19, which are the first proteins to elicit an E. canis-specific antibody response, and gp200 and p28, which elicit strong antibody responses later in the acute phase of the infection. In this report, the sensitivities and specificities of five recombinant E. canis proteins for the immunodiagnosis of E. canis infection by an enzyme-linked immunosorbent assay (ELISA) were evaluated. Recombinant polypeptides gp36, gp19, and gp200 (N and C termini) exhibited 100% sensitivity and specificity for immunodiagnosis by the recombinant glycoprotein ELISA compared with the results obtained by an indirect fluorescent-antibody assay (IFA) for the detection of antibodies in dogs that were naturally infected with E. canis. Moreover, the enhanced sensitivities of gp36 and gp19 for immunodiagnosis by the recombinant glycoprotein ELISA compared to those obtained by IFA were demonstrated with dogs experimentally infected with E. canis, in which antibodies were detected as much as 2 weeks earlier, on day 14 postinoculation. gp36 and gp19 were not cross-reactive with antibodies in sera from E. chaffeensis-infected dogs and thus provided species-specific serologic discrimination between E. canis and E. chaffeensis infections. This is the first demonstration of the improved detection capability of the recombinant protein technology compared to the capability of the “gold standard” IFA and may eliminate the remaining obstacles associated with the immunodiagnosis of E. canis infections, including species-specific identification and the lack of sensitivity associated with low antibody titers early in the acute phase of the infection.

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