• Title/Summary/Keyword: antigen detection

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Serum Antigen and Antibody Detection in Echinococcosis: Application in Serodiagnosis of Human Hydatidosis

  • Sadjjadi, Seyed Mahmoud;Sedaghat, Farzaneh;Hosseini, Seyed Vahid;Sarkari, Bahador
    • Parasites, Hosts and Diseases
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    • v.47 no.2
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    • pp.153-157
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    • 2009
  • Diagnosis of hydatidosis is based on immunodiagnostic methods along with radiological and ultrasound examinations. The objectives of the present study were to develop a specific and simple antigen-based ELISA method for diagnosis of hydatidosis and compare it with antibody detection method. The subjects in this study included 89 patients in the following groups: surgically confirmed hydatidosis patients (35 cases), control with other parasitic diseases (29 cases), and healthy controls (25 cases). Hyperimmune serum was raised against hydatid cyst fluid in rabbits. Anti-hydatid cyst IgG was purified by affinity chromatography using protein A column and labeled with horseradish peroxidase. Collected sera were assessed for hydatid cyst antigens and antibody by ELISA. Circulating hydatid antigen was found in 9 out of 35 patients with surgically confirmed hydatidosis. A sensitivity of 25.7% and a specificity of 98.0% were calculated for the antigen detection assay. Antibody detection by indirect ELISA, using antigen B, showed that 94.2% of patients (33 cases) have anti-hydatid cyst antibodies in their serum while cross reaction was noted in a few of non-hydatidosis patients. A sensitivity of 94.2% and specificity of 81.6% were found for the antibody detection assay. Findings of this study indicated that antibody detection assay is a sensitive approach for diagnosis of hydatid cyst while antigen detection assay might be a useful approach for assessment of the efficacy of treatment especially after removal of the cyst.

An Improved Method for Detection of Salmonella Typhi O Antigen with Staphylococcal Protein A Using Enzyme Immunoassay (포도구균의 A단백질을 이용한 효소면역법으로 살모넬라 O항원 검출)

  • Rhyu, Mun-Gan;Kim, Gum-Ryong;Lee, Choong-Ki
    • The Journal of the Korean Society for Microbiology
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    • v.22 no.4
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    • pp.445-451
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    • 1987
  • Coagglutination method is widely used for the diagnosis of Salmonella infection. This test, however, has a disadvantage of false positive reaction due to the coagglutination of staphylococci with non-specific immune complexes or anti-staphylococci antibody in serum. Salmonell O antigen was detected by enzyme immunoassay with protein A-bearing Staphylococcus aureus as in the solid phase. Horse radish peroxidase was labeled to IgG specific against Salmonella O antigen. This enzyme immunoassay was much more sensitive than conventional coagglutination method without false poitive agglutination. To improve the sensitivity for detection of Salmonella O antigen in samples, we tried to determine the optimal concentration of normal IgG that inhibits non-specific binding of horse radish peroxidase labeled IgG to staphylococci, and to establish the optimal condition of reaction between antigen-antibody complex and staphylococci. Non-specific binding of horse radish peroxidase labeled specific IgG to staphylococci was almost blocked when the enzyme labeled IgG was 500-fold diluted with phosphate buffered saline containing 2mg/ml of normal IgG. When staphylococci coated with antibody to Salmonella O antigen were mixed with antigen-antibody complex and then incubated for 1 hour at room temperature, the minimal detectable concentration of Salmonella O antigen was 1ng/ml. The sensitivity of enzyme immunoassay was 100-fold greater than a conventional coagglutination method. This enzyme immunoassay could be expected as an improved method for detection of other infectious agents.

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Detection of bovine rotavirus antigen by enzyme linked immunosorbent assay (효소면역법에 의한 소 로타바이러스 항원 검출)

  • 안재문;유기조;이용희;이종인
    • Korean Journal of Veterinary Service
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    • v.19 no.1
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    • pp.30-38
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    • 1996
  • Enzyme-linked immunosorbent assay (ELISA) was developed to detect rotavirus antigen in fecal samples using VP6-specific monoclonal antibody(2B12). The ELISA for rotavirus antigen detection found to have specificity to all bovine and porcine rotaviruses tested but not to bovine viral diarrhea virus and bovine coronavirus. The ELISA appeared to have similar sensitivity and specificity compared to fluorescence antibody assay(FA) and electropherotyping (PAGE).

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Study on Antibody-enzyme Coupling and Enzyme Immunoassay Methods (효소-항체의 결합 및 효소면역측정 방법의 연구)

  • Jang Sean Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.3
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    • pp.874-879
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    • 2004
  • Alakaline phosphatase (ALP)- or horseradish peroxidase (HRP)-antibody conjugate was used frequently on the immunological detection methods such as enzyme-linked immunosobent assay (ELISA), immunobolt, immunohistochemistry. The classical enzyme-antibody coupling method by one-step (direction) injection of glutaraldehyde bring into being disadvantage such as low sensitivity of antigen detection because of homopolymers. This study was modified with the dialysis glutaraldehyde method to provide simple coupling through E-amino residues present in most protein. The dialysis glutaraldehyde coupling effects were better than the classical one-step glutaraldehyde injection in antigen detection of ELISA and immunobolt. Optimal dose of the dialysis glutaraldehyde solution was 0.10-0.25 %. This results suggest that the dialysis glutaraldehyde coupling method can readily applied to antigen detection of in vitro and in vivo.

Protease antigen recovery induces non-specific reaction in B-Cells (Protease antigen recovery의 B-Cell에 대한 비특이반응 유발)

  • Kim, Ok-Jin;Yi, Seong-Joon
    • Korean Journal of Veterinary Pathology
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    • v.7 no.1
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    • pp.11-15
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    • 2003
  • Antigen retrieval (AR) techniques were widely used to recover the antigenicity from the fixed tissues, which were guided by the philosophy of rendering immunohistochemistry (IHC) applicable to routine formalin-fixed, paraffin-embedded tissues for wide application of IHC in research and clinical filed for morphological observation like as anatomy, histology and pathology. Protease antigen recovery (PAR) is an AR technique, which is obtained the antigen retrieve by using enzyme digestion, and commonly used in IHC field. However, during the IHC for the detection of ovine herpesvirus 2 (OvHV-2) antigen, we noted lymphocyte-like cells-specific staining in the infiltrated cells into various organs like as liver and kidney, which was also shown in the IHC tissues with isotype control. However, those signals were not observed in the tissues conducted with in situ hybridization. Therefore, we analyzed the specificity of the IHC detection results. We found that PAR may induce false-positive result during IHC in lymphocyte-like cells, which were infiltrated mainly around vessels and in interstitial tissues. Through the Phenotyping, we realized that those false-positive cells were B-cell-related cells. These results suggest that PAR, a AR using protease, may induce non-specific false-positive reactions during IHC.

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Biosensor for Detection of Yersinia enterocolitica based on imaging ellipsometry (이미지 엘립소미트리를 이용한 예시니아 검출용 바이오센서 개발)

  • Y. M. Bae;Park, K. W.;Park, J. W.;S. I. Cho
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2003.07a
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    • pp.421-426
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    • 2003
  • The Immunosensor based on antigen-antibody binding have been developed for detecting several analytes including antigen, small molecules, and cell. This method can be rapid and show very good detection limits. For Implementation of immunosensor, technologies for immobilization of antibody onto solid surface and detection of protein-protein binding must be developed. (an ellipsis)

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Double-Enhancement Strategy: A Practical Approach to a Femto-Molar Level Detection of Prostate Specific $Antigen-{\alpha}_1-Antichymotrypsin$ (PSA/ACT Complex) for SPR Immunosensing

  • Cao, Cuong;Sim, Sang-Jun
    • Journal of Microbiology and Biotechnology
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    • v.17 no.6
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    • pp.1031-1035
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    • 2007
  • Prostate specific $antigen-{\alpha}_1-antichymotrypsin$ was detected by a double-enhancement strategy involving the exploitation of both colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation. The AuNPs were synthesized and conjugated with horse-radish peroxidase-PSA polyclonal antibody by physisorption. Using the protein-colloid for SPR-based detection of the PSPJACT complex showed their enhancement as being consistent with other previous studies with regard to AuNPs enhancement, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the signal. The limit of detection was found at as low as 0.027 ng/ml of the PSA/ACT complex (or 300 fM), which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

Evaluation of Rapid Diagnostics for Plasmodium falciparum and P. vivax in Mae Sot Malaria Endemic Area, Thailand

  • Chaijaroenkul, Wanna;Wongchai, Thanee;Ruangweerayut, Ronnatrai;Na-Bangchang, Kesara
    • Parasites, Hosts and Diseases
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    • v.49 no.1
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    • pp.33-38
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    • 2011
  • Prompt and accurate diagnosis of malaria is the key to prevent disease morbidity and mortality. This study was carried out to evaluate diagnostic performance of 3 commercial rapid detection tests (RDTs), i.e., Malaria Antigen Pf/Pan$^{TM}$, Malaria Ag-Pf$^{TM}$, and Malaria Ag-Pv$^{TM}$ tests, in comparison with the microscopic and PCR methods. A total of 460 blood samples microscopically positive for Plasmodium falciparum (211 samples), P. vivax (218), mixed with P. falciparum and P. vivax (30), or P. ovale (1), and 124 samples of healthy subjects or patients with other fever-related infections, were collected. The sensitivities of Malaria Ag-Pf$^{TM}$ and Malaria Antigen Pf/Pan$^{TM}$ compared with the microscopic method for P. falciparum or P. vivax detection were 97.6% and 99.0%, or 98.6% and 99.0%, respectively. The specificities of Malaria Ag-Pf$^{TM}$, Malaria Ag-Pv$^{TM}$, and Malaria Antigen Pf/Pan$^{TM}$ were 93.3%,98.8%, and 94.4%, respectively. The sensitivities of Malaria Ag-Pf$^{TM}$, Malaria Antigen Pf/Pan$^{TM}$, and microscopic method, when PCR was used as a reference method for P. falciparum or P. vivax detection were 91.8%, 100%, and 96.7%, or 91.9%,92.6%, and 97.3%, respectively. The specificities of Malaria Ag-Pf$^{TM}$, Malaria Ag-Pv$^{TM}$, Malaria Antigen Pf/Pan$^{TM}$, and microscopic method were 66.2%, 92.7%, 73.9%, and 78.2%, respectively. Results indicated that the diagnostic performances of all the commercial RDTs are satisfactory for application to malaria diagnosis.

Clinical Significance of Combined Detection of Serum Tumor Markers in Diagnosis of Patients with Ovarian Cancer

  • Bian, Jing;Li, Bo;Kou, Xian-Juan;Liu, Tian-Zhou;Ming, Liang
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6241-6243
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    • 2013
  • Objective: To explore the predictive value of tumor markers, including cancer antigen 72-4 (CA72-4), cancer antigen 15-3 (CA15-3) and cancer antigen 125 (CA125), in single or combined detection, for the diagnosis of ovarian cancer. Methods: 120 patients diagnosed with ovarian cancer from August 2011 to March 2013 and 80 patients diagnosed with benign ovarian tumors were enrolled in this test, along with 50 health examination women randomly selected from the database as controls. Serum levels of CA72-4, CA15-3 and CA125 in this study were determined by electrochemiluminescence (ECL). Results: Serum levels of CA72-4, CA15-3 and CA125 in ovarian cancer were higher than those in healthy group and benign group (P<0.01).The sensitivity of combined detection of those three tumor markers for diagnosis of ovarian cancer was obviously higher than with single detection with each marker (P<0.01). Conclusions: CA72-4, CA15-3 and CA125 could be a good combination in the diagnosis of ovarian cancer. Patients whose tumor markers continue to increase should be highly suspected of malignancy.

Immunological Study on the Diapause of Silkworm (Bombyx mori L..) (가잠의 휴면성에 관한 면역학적 연구)

  • 마영일;박광의
    • Journal of Sericultural and Entomological Science
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    • v.15 no.2
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    • pp.1-7
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    • 1973
  • It was found that the diapause in the silkworm egg is induced by the action of the diapause hormone secreted from the suboesophageal ganglion, and "esterase A" affects protein metabolism in oocyte and egg. In this connection, some changes in protein metabolism of silkworm egg according to embryonic developments could give some information on the diapause, using Ouchterlony Test. Antigenicity of the protein of silkworm egg was detected through antigen-antibody interaction among the extracts of rabbit blood. Furthermore, existence of the specific antigen was also detected according to embryonic development, using the adsorption test. The results were obtained as follows: 1 Detection of antigenicity The antigenicity of silkworm egg was ascertained by inoculating it into a rabbit, but positive results were shown in most of the silkworm eggs tested, whereas the antibody specific to a certain antigen was not detected. 2. Detection of the common antigen It was demonstrated that most of the antigen could incite the common antibodies, but the specific antibody formation was not detected in a few antigens, even though the nonspecific antibody formation was displayed. 3. Detection of the specific antigen It is suggested that there are the specific antigens detectable in each treated eggs by the adsorption test.

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