• Title/Summary/Keyword: Assay sensitivity

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Development of Membrane Strip Assay System for Lipoprotein Cholesterol (Membrane strip을 이용한 지질단백질 Cholesterol 측정시스템의 개발)

  • 신인수;백세환
    • KSBB Journal
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    • v.11 no.2
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    • pp.140-150
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    • 1996
  • To develop a home-version assay system for plasma lipoprotein cholesterol, variables that can control the assay performance were optimized. The system was constructcd by using two major components: nitrocellulose membrane strip with immobilized enzymes (cholesterol esterase, cholesterol oxidase, and horseradish peroxidase); and sample carrier solution containing non-ionic detergent (Triton X-100) and chromogen (3,3'-diaminobenzidine). Once a sample combined with the carrier was absorbed from the bottom of the strip, cholesterol was delivered by capillary action to the immobilized enzymes and a sequential reactions took place. In the final reaction, the chromogen was oxidized and then generated a color as signal that was proportional to the concentration of cholesterol. The signal intensity was enhanced by optimizing conditions for the immobilization of enzymes and the chemical composition of carriel. Under these conditions, a dose-response curve was obtained and revealed a high sensitivity enough to measure the cholesterol in blood.

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Multiplex PCR Assay for Simultaneous Detection of Korean Quarantine Phytoplasmas

  • Kim, Young-Hwan;Win, Nang Kyu;Back, Chang-Gi;Yea, Mi-Chi;Yim, Kyu-Ock;Jung, Hee-Young
    • The Plant Pathology Journal
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    • v.27 no.4
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    • pp.367-371
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    • 2011
  • Multiplex PCR assays were developed for the simultaneous detection of ten important Korean quarantine phytoplasmas. The species-specific primers were designed based on ribosomal protein, putative preprotein translocase Y, immunodominant protein, elongation factor TU, chaperonin protein and the 16S rRNA genes of 'Candidatus (Ca.) Phytoplasma' species. Three main primer sets were prepared from ten designed primer pairs to limit nonspecific amplification as much as possible. The multiplex PCR assay using the three primer sets successfully amplified the correct conserved genes for each 'Ca. Phytoplasma' species. In addition, ten important 'Ca. Phytoplasma' species could be easily determined by recognizing band patterns specific for each phytoplasma species from three primer sets. Moreover, a high sensitivity of multiplex PCR for each primer set was observed for samples containing a low DNA concentration (10 ng/${\mu}l$). This study provides the useful multiplex PCR assay as a convenient method to detect the presence of ten important quarantine phytoplasmas in Korea.

Study of Interferon Assay by HEp-2 : VSV system (HEp-2 : VSV system을 이용한 인터페론 역가측정 연구)

  • Jung, In Whoan;Chang, Uk;Kim, Hyun Su;Bai, Jong Chan;Lee, Won Yung
    • Microbiology and Biotechnology Letters
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    • v.13 no.1
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    • pp.27-31
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    • 1985
  • A rapid assay for interferon based on reduction of cytopathic effect was developed with HEp-2 and Vesicular Stomatitis Virus. The number of manipulations and the lengths of the various incubation steps were reduced to minimum. The assay is simple to perform and can be completed with 22-24 hr. Moreover, it was precise method than CPE-reading method.

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Dot-Blot Immunoassay of Fasciola gigantica Infection using 27 kDa and Adult Worm Regurge Antigens in Egyptian Patients

  • Kamel, Hanan H.;Saad, Ghada A.;Sarhan, Rania M.
    • Parasites, Hosts and Diseases
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    • v.51 no.2
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    • pp.177-182
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    • 2013
  • The purpose of the present study was to evaluate the potential role of the 27-Kilodalton (KDa) antigen versus Fasciola gigantica adult worm regurge antigens in a DOT-Blot assay and to assess this assay as a practical tool for diagnosis fascioliasis in Egyptian patients. Fasciola gigantica antigen of an approximate molecular mass 27- (KDa) was obtained from adult worms by a simple elution SDS-PAGE. A Dot-Blot was developed comparatively to adult worm regurge antigens for the detection of specific antibodies from patients infected with F. gigantica in Egypt. Control sera were obtained from patients with other parasitic infections and healthy volunteers to assess the test and compare between the antigens. The sensitivity, specificity, positive and negative predictive values of Dot-Blot using the adult worm regurge were 80%, 90%, 94.1%, and 69.2% respectively, while those using 27-KDa were 100% which confirms the diagnostic potential of this antigen. All patients infected with Fasciola were positive, with cross reactivity reported with Schistosoma mansoni serum samples. This 27-KDa Dot-Blot assay showed to be a promising test which can be used for serodiagnosis of fascioliasis in Egyptian patients especially, those presenting with hepatic disease. It is specific, sensitive and easy to perform method for the rapid diagnosis particularly when more complex laboratory tests are unavailable.

Evaluation of Anticancer Activity of Curcumin Analogues Bearing a Heterocyclic Nucleus

  • Ahsan, Mohamed Jawed
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1739-1744
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    • 2016
  • We report herein an in vitro anticancer evaluation of a series of seven curcumin analogues (3a-g). The National Cancer Institute (NCI US) Protocol was followed and all the compounds were evaluated for their anticancer activity on nine different panels (leukemia, non small cell lung cancer, colon cancer, CNS cancer, melanoma, ovarian cancer, renal cancer, prostate cancer and breast cancer) represented by 60 NCI human cancer cell lines. All the compounds showed significant anticancer activity in one dose assay (drug concentration $10{\mu}M$) and hence were evaluated further in five dose assays (0.01, 0.1, 1, 10 and $100{\mu}M$) and three dose related parameters $GI_{50}$, TGI and $LC_{50}$ were calculated for each (3a-g) in micro molar drug concentrations (${\mu}M$). The compound 3d (NSC 757927) showed maximum mean percent growth inhibition (PGI) of 112.2%, while compound 3g (NSC 763374) showed less mean PGI of 40.1% in the one dose assay. The maximum anticancer activity was observed with the SR (leukemia) cell line with a $GI_{50}$ of $0.03{\mu}M$. The calculated average sensitivity of all cell lines of a particular subpanel toward the test agent showed that all the curcumin analogues showed maximum activity on leukemia cell lines with $GI_{50}$ values between 0.23 and $2.67{\mu}M$.

Enzyme-linked immunosorbent assay (ELISA) for the detection of RVS (Retrovirus of Salmonid) (ELISA법을 이용한 연어과 어류의 RVS 검출(Retrovirus of Salmonid) 검출)

  • Oh, Myung-Joo;Yoshimizu, Mamoru
    • Journal of fish pathology
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    • v.9 no.2
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    • pp.169-176
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    • 1996
  • An indirect double antibody enzyme-linked immunosorbent assay (ELISA) was developed for rapid detection of a new virus isolated from abnormally swimming salmonid fish, RVS (Retrovirus of salmonid). Results using brain tissue homogenates, and infected cell cultures are described. The sensitivity of the methods is $10^{2.6}$ $TCID_{50}/100{\mu}l$ of the examined cell culture fluid. The specificity was confirmed by the ELISA inhibition test and virological examinations. Viral antigen could be detected in artificially infected fish tissue homogenates. The assay will allow the diagnosis of RVS-infected fish within a day.

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Diagnosis of Cylindrocarpon destructans Using Enzyme-Linked Immunosorbent Assay

  • Li, Taiying;Ji, Sungyeon;Jung, Boknam;Kim, Bo Yeon;Lee, Kwang Sik;Seo, Mun Won;Lee, Sung Woo;Lee, Jungkwan;Lee, Seung-Ho
    • Research in Plant Disease
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    • v.25 no.3
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    • pp.131-135
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    • 2019
  • Cylindrocarpon destructans causes ginseng root rot and produces radicicol that has an antifungal effect. In this study, we developed a method to detect this fungus using enzyme-linked immunosorbent assay (ELISA). Secreted proteins of C. destructans were used as antigens to obtain C. destructans-specific IgG from mouse. Out of 318 monoclonal antibodies generated from mouse, two antibodies (Cd7-2-2 and Cd7-2-10) showed highest specificity and sensitivity. Indirect ELISA using both antigens successfully detected C. destructans in soils, but direct ELISA using IgG conjugated with horseradish peroxidase failed to detect antigens in soils. The indirect ELISA developed here can efficiently detect the fungus and help manage ginseng root rot disease in fields.

Establishment and Application of Polymerase Spiral Reaction Amplification for Salmonella Detection in Food

  • Xu, Wenli;Gao, Jun;Zheng, Haoyue;Yuan, Chaowen;Hou, Jinlong;Zhang, Liguo;Wang, Guoqing
    • Journal of Microbiology and Biotechnology
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    • v.29 no.10
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    • pp.1543-1552
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    • 2019
  • Salmonella is a common zoonotic and foodborne pathogen that causes high morbidity and mortality in developing countries. In this study, we established and validated a polymerase spiral reaction (PSR) assay which targeted the conserved invasion gene (invA) of Salmonella by SYBR Green I indicator methods. Subsequently, assays for determination of the optimal conditions for optimal specificity and sensitivity of PSR were performed. We performed comprehensive evaluations using loop-mediated isothermal amplification (LAMP) and real-time PCR. A total number of 532 samples of daily food were analyzed by PSR. Twenty-seven bacterial strains were tested in the specificity assay, from which positive results were obtained only for 14-Salmonella strains. However, none of the 13 non-Salmonella strains was amplified. Similarly with LAMP and real-time PCR, the detection limit of the PSR assay was 50 CFU/ml. The PSR method was also successfully applied to evaluate the contamination with Salmonella in 532 samples of daily food, corroborating traditional culture method data. The novel PSR method is simple, sensitive, and rapid and provides new insights into the prevention and detection of foodborne diseases.

Comparison of Seven Commercial TaqMan Master Mixes and Two Real-Time PCR Platforms Regarding the Rapid Detection of Porcine DNA

  • Kang, Soo Ji;Jang, Chan Song;Son, Ji Min;Hong, Kwang Won
    • Food Science of Animal Resources
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    • v.41 no.1
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    • pp.85-94
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    • 2021
  • A pig-specific real-time PCR assay based on the mitochondrial ND5 gene was developed to detect porcine material in food and other products. To optimize the performance of assay, seven commercial TaqMan master mixes and two real-time PCR platforms (Applied Biosystems StepOnePlus and Bio-rad CFX Connect) were used to evaluate the limit of detection (LOD) as well as the PCR efficiency and specificity. The LODs and PCR efficiencies for the seven master mixes on two platforms were 0.5-5 pg/reaction and 84.96%-108.80%, respectively. Additionally, non-specific amplifications of DNA from other animal samples (human, dog, cow, and chicken) were observed for four master mixes. These results imply that the sensitivity and specificity of a real-time PCR assay may vary depending on master mix and platform used. The best combination of master mix and real-time PCR platform can accurately detect 0.5 pg porcine DNA, with a PCR efficiency of 100.49%.

A rapid and quantitative fluorescent microsphere immunochromatographic strip test for detection of antibodies to porcine reproductive and respiratory syndrome virus

  • Wei, Yanqiu;Yang, Baozhi;Li, Yunlong;Duan, Yongcheng;Tian, Deyu;He, Baoxiang;Chen, Chuangfu;Liu, Wenjun;Yang, Limin
    • Journal of Veterinary Science
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    • v.21 no.4
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    • pp.68.1-68.8
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    • 2020
  • A fluorescent microsphere-based immunochromatographic strip test (FICT) was developed for the rapid, sensitive, and quantitative detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies at the pen-side. The assay was based on the formation of a sandwich immune-complex (anti-pig IgG-PRRSV antibodies-NSP7/N), which was validated by a comparison with IDEXX-ELISA using 3325 clinical specimens. The diagnostic specificity, sensitivity, and accuracy of FICT were 97.28, 93.41, and 94.95%, respectively. FICT showed a good correlation with the virus neutralization assay. Overall, a promising pen-side diagnostic tool was developed for the rapid and quantitative detection of PRRSV antibodies within 15 min.