• 제목/요약/키워드: gold assay

검색결과 118건 처리시간 0.02초

A Modified Quantum Dot-Based Dot Blot Assay for Rapid Detection of Fish Pathogen Vibrio anguillarum

  • Zhang, Yang;Xiao, Jingfan;Wang, Qiyao;Zhang, Yuanxing
    • Journal of Microbiology and Biotechnology
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    • 제26권8호
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    • pp.1457-1463
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    • 2016
  • Vibrio anguillarum, a devastating pathogen causing vibriosis among marine fish, is prevailing in worldwide fishery industries and accounts for grievous economic losses. Therefore, a rapid on-site detection and diagnostic technique for this pathogen is in urgent need. In this study, two mouse monoclonal antibodies (MAbs) against V. anguillarum, 6B3-C5 and 8G3-B5, were generated by using hybridoma technology and their isotypes were characterized. MAb 6B3-C5 was chosen as the detector antibody and conjugated with quantum dots. Based on MAb 6B3-C5 labeled with quantum dots, a modified dot blot assay was developed for the on-site determination of V. anguillarum. It was found that the method had no cross-reactivity with other than V. anguillarum bacteria. The detection limit (LOD) for V. anguillarum was 1 × 103 CFU/ml in cultured bacterial suspension samples, which was a 100-fold higher sensitivity than the reported colloidal gold immunochromatographic test strip. When V. anguillarum was mixed with turbot tissue homogenates, the LOD was 1 × 103 CFU/ml, suggesting that tissue homogenates did not influence the detection capabilities. Preenrichment with the tissue homogenates for 12 h could raise the LOD up to 1 × 102 CFU/ml, confirming the reliability of the method.

Wheat phytase potentially protects HT-29 cells from inflammatory nucleotides-induced cytotoxicity

  • Jeongmin An;Jaiesoon Cho
    • Animal Bioscience
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    • 제36권10호
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    • pp.1604-1611
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    • 2023
  • Objective: The aim of this study was to investigate the protective effect of wheat phytase as a structural decomposer of inflammatory nucleotides, extracellular adenosine triphosphate (ATP), and uridine diphosphate (UDP) on HT-29 cells. Methods: Phosphatase activities of wheat phytase against ATP and UDP was investigated in the presence or absence of inhibitors such as L-phenylalanine and L-homoarginine using a Pi Color Lock gold phosphate detection kit. Viability of HT-29 cells exposed to intact- or dephosphorylated-nucleotides was analyzed with an EZ-CYTOX kit. Secretion levels of pro-inflammatory cytokines (IL-6 and IL-8) in HT-29 cells exposed to substrate treated with or without wheat phytase were measured with enzyme-linked immunosorbent assay kits. Activation of caspase-3 in HT-29 cells treated with intact ATP or dephosphorylated-ATP was investigated using a colorimetric assay kit. Results: Wheat phytase dephosphorylated both nucleotides, ATP and UDP, in a dose-dependent manner. Regardless of the presence or absence of enzyme inhibitors (L-phenylalanine and L-homoarginine), wheat phytase dephosphorylated UDP. Only L-phenylalanine inhibited the dephosphorylation of ATP by wheat phytase. However, the level of inhibition was less than 10%. Wheat phytase significantly enhanced the viability of HT-29 cells against ATP- and UDP-induced cytotoxicity. Interleukin (IL)-8 released from HT-29 cells with nucleotides dephosphorylated by wheat phytase was higher than that released from HT-29 cells with intact nucleotides. Moreover, the release of IL-6 was strongly induced from HT-29 cells with UDP dephosphorylated by wheat phytase. HT-29 cells with ATP degraded by wheat phytase showed significantly (13%) lower activity of caspase-3 than HT-29 cells with intact ATP. Conclusion: Wheat phytase can be a candidate for veterinary medicine to prevent cell death in animals. In this context, wheat phytase beyond its nutritional aspects might be a novel and promising tool for promoting growth and function of intestinal epithelial cells under luminal ATP and UDP surge in the gut.

Measurement of Antibodies to Varicella-Zoster Virus Using a Virus-Free Fluorescent-Antibody-to-Membrane-Antigen (FAMA) Test

  • Park, Rackhyun;Hwang, Ji Young;Lee, Kang Il;Namkoong, Sim;Choi, Seuk-Keun;Park, Songyong;Park, Hosun;Park, Junsoo
    • Journal of Microbiology and Biotechnology
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    • 제25권2호
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    • pp.268-273
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    • 2015
  • The fluorescent-antibody-to-membrane-antigen (FAMA) test is regarded as the "gold standard" to detect protective antibodies to varicella-zoster virus (VZV) because of its high sensitivity and specificity. Because the classic FAMA test uses an infectious virus for detection of antibodies to VZV, it is labor-intensive, and also requires special equipment for handling the virus. For this reason, we attempted to develop a simple and safe FAMA assay. Because VZV glycoprotein E (gE) is one of the major VZV glycoproteins, we used the gE protein for the FAMA test (gE FAMA). Here, we demonstrate that overexpression of gE in HEK293T cells can be used to measure antibodies in human serum, and that gE FAMA titers are closely correlated with gpEIA ELISA data. These results indicate that our gE FAMA test has the potential to measure antibodies to VZV.

Alternatives to In Vivo Draize Rabbit Eye and Skin Irritation Tests with a Focus on 3D Reconstructed Human Cornea-Like Epithelium and Epidermis Models

  • Lee, Miri;Hwang, Jee-Hyun;Lim, Kyung-Min
    • Toxicological Research
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    • 제33권3호
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    • pp.191-203
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    • 2017
  • Human eyes and skin are frequently exposed to chemicals accidentally or on purpose due to their external location. Therefore, chemicals are required to undergo the evaluation of the ocular and dermal irritancy for their safe handling and use before release into the market. Draize rabbit eye and skin irritation test developed in 1944, has been a gold standard test which was enlisted as OECD TG 404 and OECD TG 405 but it has been criticized with respect to animal welfare due to invasive and cruel procedure. To replace it, diverse alternatives have been developed: (i) For Draize eye irritation test, organotypic assay, in vitro cytotoxicity-based method, in chemico tests, in silico prediction model, and 3D reconstructed human cornealike epithelium (RhCE); (ii) For Draize skin irritation test, in vitro cytotoxicity-based cell model, and 3D reconstructed human epidermis models (RhE). Of these, RhCE and RhE models are getting spotlight as a promising alternative with a wide applicability domain covering cosmetics and personal care products. In this review, we overviewed the current alternatives to Draize test with a focus on 3D human epithelium models to provide an insight into advancing and widening their utility.

Functional Analysis of the Tomato Spotted Wilt Virus(TSWV) NSm Protein by Using Immunoblotting and Immunogold Labelling Assay

  • Choi, Tae-Jin
    • Journal of Microbiology and Biotechnology
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    • 제6권6호
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    • pp.468-473
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    • 1996
  • The genome of tomato spotted wilt virus (TSWV) is composed of three RNA segments, S, M, and L RNA and the 5.0 kb M RNA encodes two glycoproteins Gl, G2 and NSm protein of unknown function. In an effort to investigate the function of the NSm protein, antibody was raised against NSm fusion protein overexpressed in Escherichia coli. This antibody was used to detect the NSm protein by using western blot analysis and electron microscopic observation after immunogold labelling. For the cloning of the NSm gene, total RNA extracted from a TSWV infected plant was used for cDNA synthesis and polymerase chain reaction (PCR) instead of going through time-consuming virus purification. A protein band specifically reacting to the NSm antibody was detected from TSWV inoculated plants. The NSm protein was detected in the cell wall fraction and in pellet from low speed centrifugation when the infected plant tissue was fractionated into 4 fractions. In the immuno-electron microscopic observation, gold particles were found around the plasmodesmata of infected plant tissue. These results suggest that the NSm protein of TSWV plays some role in cell-to-cell movement of this virus.

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의료기관 종사자의 잠복결핵감염 유병률과 위험요인 분석 (Analysis of Prevalence and Risk Factors for Latent Tuberculosis Infection among Healthcare Workers)

  • 이재백;최정실
    • Journal of Korean Biological Nursing Science
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    • 제21권4호
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    • pp.300-307
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    • 2019
  • Purpose: The purpose of this study was to provide basic data on the infection prevention management program, which is one of the infectious disease control program by identifying the prevalence and risk factors of latent tuberculosis infection (LTBI) in healthcare workers. Methods: We surveyed a total of 3,046 LTBI test results, including those of 2,269 existing staff and 777 new employees. An interferon-gamma release assay (IGRA) for the diagnosis of LTBI was performed using QuantiFERON®-TB Gold In-Tube (QFT-IT). The risk factors of LTBI were analyzed using logistic regression analysis. Results: The overall prevalence of LTBI was 16.0% (487/3,046). The prevalence of LTBI in the existing staff was 17.9% (406/2,269) and the prevalence of LTBI in new employees was 10.4% (81/777). Multivariate logistic regression analysis revealed that the risk factors of latent tuberculosis infection among the existing staff were gender, age and work period wheres, the risk factor amongst the new employees depended on their age. Conclusion: The LTBI was not related to the type of occupation and work unit. Therefore, while establishing an infection control program for the prevention of tuberculosis infection at medical institurions, institutional heads and infection control experts should encompass a policy for all the employees.

Microfabricated Cell Chip for Cell-based in vitro Assay

  • 박제균;김태한;이상은;김수현;윤규식;이정건
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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    • pp.115-118
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    • 2000
  • 미세 가공 기술을 이용하여 제작된 IDA 전극을 활용하여 임피던스 측정방식의 cell chip으로의 응용에 대해 고찰하였다. IDA 전극은 기존의 반도체 공정으로서 손쉽게 제작할 수 있고, 대량 제작시 전극의 재현성 확보가 용이하고 소형화 할 수 있으며 낮은 단가로 제작될 수 있는 장점이 있다. IDA 전극을 채용한 cell chip을 B16-F1 melanoma 세포 배양에 적용한 결과, 세포성장과 임피던스 변화량이 상관성을 보였고, 세포의 성장을 저해하는 약물의 투과시 cell chip의 임피던스 변화 역시 기존의 방법과 유사한 결과를 보여 주었다.

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전자현미경 기법을 이용한 Herpes simplex 2형 바이러스 항원의 면역학적 분석 (Immunoelectron Microscopic Localization and Analysis of Herpes simplex Virus Type 2 Antigens)

  • 김천식;오명환
    • 미생물학회지
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    • 제40권1호
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    • pp.23-28
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    • 2004
  • 단순포진 바이러스 감염을 유발하는Herpes simplex2형 바이러스의 감염에 관여하는 항원들과 중화항체 생산을 유발하는 주요 항원들의 위치를 확인하였다. Vero cell에 감염하였을 때 48시간 동안 31, 43, 59, 69 kDa 바이러스 항원들이 지속적으로 발현되었으며, 감염된 쥐에서 생산한 항체와의 반응에서는 51 kDa 항원이 가장 강한 반응을 보였다. 면역전자현미경으로 위치를 확인한 결과 colloidal gold가 바이러스 표면에 발견되는 것으로 보아 이 항원이 바이러스 표면에 존재하고 있는 것으로 확인되었다. 형광현미경 분석은 이 항원들이 감염된 세포 내에서 전반적으로 발견되었고 특히 세포 표면에서 많이 발현되고 있었다.

Increasing of Macrophage Migration Inhibitory Factor Expression in Human Patients Infected with Virulent Brucella in Iraq

  • Khudhur, Hasan R.;Menshed, Abbas Ali;Hasan, Ahmed Abbas
    • 한국미생물·생명공학회지
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    • 제48권4호
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    • pp.569-573
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    • 2020
  • Brucellosis is a zoonotic disease caused by Brucella infections and humans usually contract this disease from close contact with infected animals or their products, usually via the ingestion of cheese or crude milk. Macrophage migration inhibitory factor (MIF) and Pro- and anti-inflammatory cytokines play an important role in susceptibility/resistance and the immunopathogenesis of Brucella infection. These cytokines are crucial factors in the initiation and progression of protective immunity against Brucella infection but the role of MIF has not been well studied in the human response to intracellular microbes. This study was designed to investigate the effect of MIF expression on Brucella susceptibility. A total of 85 positive rose Bengal tests and 24 samples from healthy individuals were collected for this study and subjected to polymerase chain reaction assays (PCR) of the bcsp31 diagnostic gene. MIF concentrations were evaluated using Enzyme-Linked immunosorbent assay (ELISA) and the results showed that 46 (54%) of the rose Bengal test samples were positive and 39 (46%) were negative for bcsp31 (p ≤ 0.05) and used as the gold standard for all of the comparisons in this study. The ELISA results indicate that the mean concentration of MIF was significantly higher in patients with positive rose Bengal tests when compared to the control groups and that its concentration increases with increasing age in both the patient and control groups (p ≤ 0.05).

Validation of Synovial Fluid Clinical Samples for Molecular Detection of Pathogens Causing Prosthetic Joint Infection Using GAPDH Housekeeping Gene as Internal Control

  • Jiyoung Lee;Eunyoung Baek;Hyesun Ahn;Youngnam Park;Geehyuk Kim;Sua Lim;Suchan Lee;Sunghyun Kim
    • 대한의생명과학회지
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    • 제29권4호
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    • pp.220-230
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    • 2023
  • Identification of the pathogens causing infection is important in terms of patient's health management and infection control. Synovial fluids could be used as clinical samples to detect causative pathogens of prosthetic joint infections (PJIs) using molecular diagnostic assays, therefore, normalization and validation of clinical samples are necessary. Microbial culture is considered the gold standard for all infections, including PJIs. Recently, molecular diagnostic methods have been developed to overcome the limitation of microbial culture. Therefore, guideline for validating clinical samples to provide reliable results of molecular diagnostic assays for infectious diseases is required in clinical field. The present study aimed to develop an accurate validating method of synovial fluid clinical samples using GAPDH gene as an internal control to perform the quantitative PCR TaqMan probe assay to detect pathogens causing PJIs.