• Title/Summary/Keyword: Sandwich ELISA

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Application of Oral Fluid Sample to Monitor Porcine circovirus-2 Infection in Pig Farms (구강액을 이용한 양돈장의 Porcine circovirus-2 감염에 대한 모니터링)

  • Kim, Won-Il
    • Journal of Veterinary Clinics
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    • v.27 no.6
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    • pp.704-712
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    • 2010
  • Porcine circovirus-2 (PCV2) has been implicated in many clinical diseases/syndromes that are now referred to as PCV-associated diseases (PCVAD). Due to significant economic losses caused by PCVAD, many swine operations have launched extensive monitoring programs for PCV2. Traditional serum sampling is, however, rather expensive and laborious, hampering effective large scale pathogen surveillance. A field-based longitudinal study was conducted to assess the utility of pen-based oral fluid sample as an alternative to serum for herd PCV2 testing. Six pens (25 pigs/pen) at each of 3 different sites were used in the study. One oral fluid and 5 random serum samples per pen were collected at 3, 5, 8, 12, and 16 weeks of age, and the sera were pooled by pen for testing. All samples were tested for PCV2 by real-time PCR and for antibodies by indirect fluorescent antibody test (for both anti-PCV2 IgG and IgA) and 3 ELISA assays (blocking ELISA, indirect ELISA, and IgG/IgM sandwich ELISA). PCV2 DNA was detected in oral fluid samples sporadically until 8 weeks and in all pens at 16 weeks. PCV2-specific IgG was detected in oral fluid samples at 3 weeks and persisted until 5 to 8 weeks in all sites. Anti-PCV2 IgG and IgA were detectable in oral fluid samples collected at 16 weeks from all of the pens at 1 site. The detection of PCV2 and anti-PCV2 antibody in oral fluid samples correlated positively with results on pooled sera, suggesting that oral fluids can be a cost-effective alternative to serum for herd monitoring of PCV2 infection.

Comparison of an Immunochromatographic Assay Kit with DAS-ELISA for Large-Scale Diagnosis and Molecular Discrimination of Satsuma Dwarf Virus Collected from Citrus Orchards

  • Kato, Mitsuhiro;Tomimura, Kenta;Ishii, Kanako
    • The Plant Pathology Journal
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    • v.36 no.5
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    • pp.509-514
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    • 2020
  • Satsuma dwarf virus (SDV) seriously damages citrus production by reducing the quality and yield of fruit. To avoid contamination with SDV, mother trees are checked to be SDV-free in advance of nursery tree distribution. In this study, we compared an immunochromatographic assay (ICA) kit with double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for large-scale diagnosis of SDV in orchardgrown trees in Shizuoka Prefecture, Japan. The two methods gave conflicting results for 11 of 1,705 samples, all of which were negative by DAS-ELISA but positive by ICA. The samples scored as positive by either DAS-ELISA or ICA were analyzed by reverse transcription polymerase chain reaction and all were confirmed to be positive. These results validate the use of ICA as a screening method for large-scale diagnosis. Strain discrimination revealed that 16 of 22 isolates belonged to SDV, while citrus mosaic virus (CiMV) infection only and co-infection (SDV and CiMV) were in a minority.

Immunological Characterization of Vibrio vulnificus isolated from Marine Environment (해양에서 분리한 Vibrio vulnificus의 면역학적 특성)

  • Jung, Cho-Rok;Jeon, You-Jin;Heo, Moon-Soo
    • Korean Journal of Environmental Biology
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    • v.19 no.4
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    • pp.302-312
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    • 2001
  • Immunoglobulin G was purified by 40% $(NH_4)_2SO_4$ precipitation, DEAE-Sephadex, Sephadex G-150 column chromatographies from rabbit antiserum against V. vulnificus ATCC 27562 O antigen and used for immunological test for V. vulnificus isolates. The profiles of cell lysate total protein and outer membrane protein from the isolates were analyzed by SDS-PAGE and densitometry. The overall profiles in all isolates were similar. Distict protein band was observed in comparison with V. parahaemolyticus. Western Blotting with rabbit Immunoglobulin G against cell lysates and OMP of V. vulnificus isolates showed a strong antigenic response to antigen 66, 60, 54, 48, 33 and 26 kDa which were common to all strains examined. The 26 kDa antigen showed V. vulnificus specific antigen in comparison with Vibrio parahaemolyticus. A sandwich enzyme-linked immunosorbent assay was developed by using rat anti-V. vulnificus ATCC 27562 polyclonal antibodies as capture antibody, a purified rabbit IgG antibody as detector antibody, and goat anti-rabbit IgG-alkaline phosphatase conjugate as developer antibody. When four V. vulnificus isolates were tested, the reactivity showed from 50 to 70% by sandwich ELISA.

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Antibody derived from insect glycosaminoglycan

  • Ahn, Mi Young;Hwang, Jae Sam;Yoon, Hyung Joo;Yun, Eun Young
    • International Journal of Industrial Entomology and Biomaterials
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    • v.29 no.2
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    • pp.214-219
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    • 2014
  • We prepared antibodies from insect glycosaminoglycans (GAGs) and assayed the titer. Nine polyclonal antibodies against insect GAGs were raised for development of an ELISA in biological fluids (mice serum). The 3th booster collection of antiserum of BALB/c mice as a primarily antibody was assayed for titer determination by ELISA method. In sandwich ELISA of GAGs derived from Isaria sinclairii or other insects, antiserum from insect GAGs gave satisfactory results for so potent antibody(100: 1~1000:1) raising (manufacturing) agent in range of 10 ng/ml.

Quantitation of Plasma Apolipoprotein A-I with a Sandwich Type Enzyme-Linked Immunosorbent Assay Using Monoclonal Antibodies

  • Lee, Min-Gyu;Kang, Jae-Seon;Jeong, Jae-Yeon;Jue, Dae-Myung;Kim, Hack-Joo
    • BMB Reports
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    • v.30 no.6
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    • pp.390-396
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    • 1997
  • A sandwich-type enzyme-linked immunosorbent assay (ELISA) for the quantification of human apolipoprotein A-I (apoA-I) was developed using monoclonal antibodies. For this assay, we used three monoclonal antibodies to trap and detect apo A-I. HDAI16 and HDA15 monoclonal antibodies were used for trapping apoA-I and HDAI8 monoclonal antibody was for detecting apoA-I. These three monoclonal antibodies were produced by immunizing mice with high density lipoprotein (HDL) isolated from human plasma. By immunoblot analysis, these three monoclonal antibodies were specific to apoA-I and showed no cross-reactivities with other plasma proteins. The results of competition assays for epitope cross-reactivity test also verified that these monoclonal antibodies identified separate and distinct epitopes on HDL and apoA-I. Affinity constants of monoclonal antibodies were measured by ELISA. Their association constants ranged from $10^7$ to $10^8$ $M^{-1}$. For this assay, pure apoA-I was isolated by affinity chromatography using monoclonal antibodies. In this sandwich assay, the amount of HRP-labeled HDAI8 bound to apoA-I trapped by HDAI16 and HDAI5 was proportional to apoA-I concentration in the range of 0 to 500ng/ml. ApoA-I concentration in plasma was calculated from the linear regression equation of standard curve. The precision and reliability of the assays are reflected in the low intra-and interassay coefficients of variation that averaged 3.25% and 4.30%, respectively. This assay is sensitive, simple, reproducible, convenient in incubation interval, and does not use radioisotope: thus it can be widely applied in clinical laboratories.

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Interleukin-5 Inhibition Assay of the Oriental Materia Medica Treatment by Sandwich ELISA on Mouse Splenocytes (ELISA를 이용한 IL-5 분비조절 한약물 Screening)

  • Park, Ki-Bok;Jung, Sung-Ki;Jung, Hee-Jae
    • The Journal of Internal Korean Medicine
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    • v.30 no.3
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    • pp.582-593
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    • 2009
  • Background and Objective : Allergy is defined as an altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen. This study was to evaluate the effect of oriental materia medica on IL-5 secretion in the mouse spleen cell. Methods : We used the splenocytes of mouse 8 weeks after its birth, and then cultivated those into the 2 experimental groups and a control group for 48 hours. The culture media of the experimental groups were made of $1{\mu}g/ml$, $10{\mu}g/ml$ oriental materia medica, representative. And the culture media of control group was given no oriental materia medica. Then, we assayed the quantity of cytokine-expression by the sandwich ELISA. The quantities of cytokine-expression of the experimental groups were compared with that of the control group, which was standardized. These methods were used for all of the oriental materia medica treated. Results : Some oriental materia medica inhibit the secretion of IL-5 in both $1{\mu}g/ml$ and $10{\mu}g/ml$ culture media. These were Acori Rhizoma, Luffae Fasciculus Vascularis, Amomi Rotundi Fructus, Schisandrae Fructus, Biotae Semen, Clematis armandii, Dioscoreae Sativa Rhizoma, Coicis Semen, Sophorae Flos, Oroxyli Semen, Aurantii Semen, Pini Nodi Lignum. Conclusion : This study indicates that some oriental materia medica inhibit the secretion of IL-5 and are beneficial for allergic disease.

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Detection of circulating antigens in rats experimentally infected with Paragonimus westermani by ELISA (ELISA법을 이용한 폐흡충 감염 백서의 혈청내 항원 검출)

  • 용태순;김동수
    • Parasites, Hosts and Diseases
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    • v.25 no.2
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    • pp.141-148
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    • 1987
  • Circulating antigens in rats experimentally infected with Paragonimus westermani were examined by ELISA. From a total of 22 albino rats, each fed with 25 metacercariae, blood samples were collected until 12 weeks after infection. The specific antibodies against P. westermani in the serum of an infected cat were purified by ammonium sulfate precipitation, DEAE anion-exchange chromatography and affinity chromatography serially. So-called double antibody sandwich ELISA method was used for the detection of circulating antigens. The results were as follows: Mean value of O.D. in control sera was O. 04 (S.D.=0. 04). After infection, mean O.D.(S.D.) values were changed serially: 0.03(0.01) at 0.5 week(3 days), 0.55(0.50) at 1 week, 0.69(0.45) at 1.5 week, O.20 (0.19) at 2 weeks and O.13(0.10) at 2.5 weeks of infection. They returned, thereafter, to the level before infection. When O. 16 (mean+3 S.D.) were considered as cut-off value, those higher than O. 16 were observed only in the sera collected between 1 and 2.5 weeks after infection. Average 8. 4 immature worms (2.2 from the lungs and pleural cavities; 6.2 from muscles) were recovered in a rat at 12 weeks after infection. The fact that circulating antigens were not detected after 3 weeks of infection was considered to the caused by the formation of antigen-antibady complexs.

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Production of Polyclonal Antibody against Grapevine fanleaf virus Movement Protein Expressed in Escherichia coli

  • Koolivand, Davoud;Bashir, Nemat Sokhandan;Behjatnia, Seyed Aliakbar;Joozani, Raziallah Jafari
    • The Plant Pathology Journal
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    • v.32 no.5
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    • pp.452-459
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    • 2016
  • The genomic region of Grapevine fanleaf virus (GFLV) encoding the movement protein (MP) was cloned into pET21a and transformed into Escherichia coli strain BL21 (DE3) to express the protein. Induction was made with a wide range of isopropyl-${\beta}$-D-thiogalactopyranoside (IPTG) concentrations (1, 1.5, and 2 mM) each for duration of 4, 6, or 16 h. However, the highest expression level was achieved with 1 mM IPTG for 4 h. Identity of the expressed protein was confirmed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western blotting. The expressed 41 kDa protein was purified under denaturing condition by affinity chromatography, reconfirmed by Western blotting and plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA) before being used as a recombinant antigen to raise polyclonal antibodies in rabbits. Purified anti-GFLV MP immunoglobulines (IgGs) and conjugated IgGs detected the expressed MP and GFLV virions in infected grapevines when used in PTA-ELISA, double antibody sandwich-ELISA, and Western blotting. This is the first report on the production of anti-GFLV MP polyclonal antibodies and application for the virus detection.

A detection method for vibrio vulnificus using monoclonal antibodies

  • Chung, Mi-Sun;Rim, Bung-Moo;Boong, Uhm-Tae;Park, Moon-Kook
    • Journal of Microbiology
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    • v.35 no.2
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    • pp.87-91
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    • 1997
  • Monoclonal antibodies were prepared in order to an assay method for Vibrio vulnificus. Sixteen mouse ybridoma cell lines were established by immunization of whole cell antigen to BALB/c mice, fusion with SP2/O myeloma cells, and cloning. Most of them secreted IgM.lambda. antibodies. A sandwich enzyme-linked immunosorbent assay was developed with rabbit anti-V. vulnificus polyclonal antibodies as capture antibody, an IgM monoclonal antibody as detector antibody, and goat anti-mouse IgM-alkaline phosphatase conjugate as developer antibody. The range of detection was 10$\^$4/ to 10 V. vulnificus cells per microplate well. When four related Vibrio species were tested for cross-reactions, V. parahaemolyticus showed 3.5% reactively and V. carchariae, V. fluvialis, and V. furnisii showed negligibal (<1%) cross-reactivity.

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Production of the Monoclonal Antibodies to the Escherichia coli Heat-Stable Enterotoxin (대장균의 내열성장독소 측정법개발을 위한 단세포군항체의 생산)

  • Chang, Woo-Hyun;Lee, Woo-Kon;Kim, Suck-Yong;Park, Jung-Bum
    • The Journal of the Korean Society for Microbiology
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    • v.22 no.4
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    • pp.377-392
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    • 1987
  • Monoclonal antibody to the Escherichia coli heat-stable enterotoxin(ST) was produced to develop a rapid and convenient diagnostic method to the ST. The toxin was purified from culture supernatant of enterotoxigenic E. coli O148H28($ST^+/LT^+$) and conjugated to bovine serum albumin(BSA). The ST-BSA conjugate was used to immunize BALB/c mice and the immune spleen cells from these mice were fused with $P3{\times}63$ Ag8.V653 plasmacytoma cells. Hybridomas were screened by ELISA and positive hybridomas were cloned by limiting dilution. Finally, one stable clone (AS36) specific to ST was selected for further growth and characterization. Antibody titers of culture supernatant and ascitic fluid from BALB/c mice were 1:1,024 and 1:20,480 respectively in ELISA. The isotype and subclass of monoclonal antibody was IgG1 in sandwich ELISA. To test the neutralizing effect of monoclonal antibody on toxin activity of ST, mixture of ascitic fluid and ST was assayed by infant mouse assay and this monoclonel antibody was proved to be a neutralizing antibody. The titer of ascitic fluid which completely neutralized biological activity of 4 units of ST was 1:4. Purified ST was quantitatively measured by competitive ELISA and minimum amount of ST detectable by this assay was 250pg, which was an amount six-fold smaller than that detectable by infant mouse assay. Four reference strains of enterotoxigenic E. coli from WHO were detected by competitive ELISA and highly specific, sensitive and reproducible result was obtained.

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