• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.427-430
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• 2014

We developed a novel immunochromatographic assay (ICA) (EZ-Step VanA rapid kit; Dinona, Korea) for the detection of VanA ligase from vancomycin-resistant enterococci (VRE). Of eight monoclonal antibodies screened by ELISAs, the VanA ligase ICA constructed with 1H9 plus 3G11 showed the greatest reactivity. The detection limit of the kit was $6.3{\times}10^6$ CFU per test. Of 127 vancomycin-resistant microorganisms, 100 vanA VRE were positive in the VanA ligase ICA, and 27 non-vanA vancomycin-resistant isolates were negative. These results were consistent with those of the PCR analyses. Thus, our ICA is a reliable and easy-to-use immunological assay for detecting VanA-producing VRE in clinical laboratories.

• 한국축산식품학회지
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• 제37권4호
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• pp.599-605
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• 2017

Korean native honey (KNH) is much more expensive than European honey (EH) in Korea, because KNH is a favored honey which is produced less than EH. Food fraud of KNH has drawn attention of the government office concerned, which is in need of a method to differentiate between KNH and EH which are produced by the Asiatic honeybee, Apis cerana and the European honeybee, Apis mellifera, respectively. A method to discriminate KNH and EH was established by using duplex polymerase chain reaction (PCR) in this study. Immunochromatographic assay (IC) was examined to analyze the duplex PCR product. The DNA sequences of primers for the duplex PCR were determined by comparing cytochrome C oxidase genes of the two honey bee species. Chelex resin method was more efficient in extracting genomic DNA from honey than the other two procedures of commercial kits. The duplex PCR amplifying DNA of 133 bp were more sensitive than that amplifying DNA of 206 bp in detecting EH in the honey mixture of KNH and EH. Agarose gel electrophoresis and IC detected the DNA of 133 bp at the ratios of down to 1% and 5% EH in the honey mixture, respectively and also revealed that several KNH products distributed by internet shopping sites were actually EH. In conclusion, the duplex PCR with subsequent IC could also discriminate between KNH and EH and save time and labor.

• 대한수의학회지
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• 제45권2호
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• pp.191-197
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• 2005

An immunochromatographic (IC) strip for the rapid detection of Salmonella spp. in the enriched sample was developed. Affinity purified Salmonella polyclonal antibody was conjugated with 40 nm colloidal gold particles which were prepared by citrate method in our laboratory. The antigen-antibody-gold complex was captured by Salmonella antibody attached to test line of nitrocellulose membrane during the capillary migration of sample. Specificity of the IC strip was calculated to be 100% (12/12) and sensitivity was 97.6% (41/42) in the test with pure cultured bacteria. Salmonella was artificially inoculated into raw pork macerated with enrichment broth. And then it was 10-fold diluted from $5.2{\times}10^{8}CFU/ml$ to 5.2 CFU/ml. The IC strip could detect $5.2{\times}10^{6}CFU/ml$ before enrichment. However, the lowest limit of detection was 5.2 CFU/ml after overnight incubation. The results indicated that the IC assay was a rapid, economical and simple method with high specificity and sensitivity for the detection of Salmonella spp. without using any equipment.

• Journal of Veterinary Science
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• 제21권4호
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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.

• 대한의생명과학회지
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• 제22권2호
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• pp.29-36
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• 2016

Among the several agents causing carbapenem resistance of Acinetobacter baumannii, the most common cause is OXA-23 ${\beta}$-lactamase, which is known to hydrolyze carbapenem. To effectively control dissemination of carbapenem-resistant Acinetobacter baumannii (CRAB), development of both rapid and easy-to-use detection methods are required. The aim of this study is to develop a novel immunochromatographic assay (ICA) for rapid detection of OXA-23 ${\beta}$-lactamase. Of the seven monoclonal antibodies (mAbs) screened by ELISA, four mAbs (4G6, 4H6, 6G4, 9A4) exhibited high reactivity. Of these four specific antibodies, the combination of 6G4/4G6 showed the greatest reactivity and this combination of mAbs (6G4/4G6 mAbs) was used to develop the OXA-23 ${\beta}$-lactamase ICA. Of 102 A. baumannii isolates tested, the OXA-23 ${\beta}$-lactamase ICA results were consistent with PCR analysis except one false positive and one false negative isolate. The overall sensitivity and specificity were 98.36% and 97.56%, respectively. In conclusion, to the best of our knowledge, we have developed the first specific antibody set to detect OXA-23 ${\beta}$-lactamase using an ICA kit. This novel ICA can be used as a reliable and easy-to-use immunological assay for detection of OXA-23 ${\beta}$-lactamase producing CRAB in clinical laboratories.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.149-152
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• 2011

A new chemiluminescence immunochromatographic analysis system with high sensitivity and high reproducibility was developed for the determination of microcystins (MCs) in water. Horse radish peroxidase (HRP) labeled microcystin monoclonal antibody was used for the sensitive chemiluminescence detection. The chemiluminescence immunochromatographic analysis system was composed of microcystin LR (MCLR)-monoclonal antibody (mAb)-Horse Radish Peroxidase (HRP) conjugate, MCLR-BSA conjugate, luminol, hydrogen peroxide mixture solution, an immunochromatographic assay strip and luminometer. To detect the concentration of microcystins in water, we utilized one spot analysis of the strip instead of flow type analysis. We could detect the microcystins in water at a concentration as low as 9.45 pg/mL with the chemiluminescence (CL) detection.

• Food Science and Biotechnology
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• 제17권3호
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• pp.623-630
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• 2008

A non-instrumental immunochromatographic (ICG) strip-test and direct competitive enzyme-linked immunosorbent assay (DC-ELISA) for aflatoxin B1 (AFB1) determination were developed and optimized. The detection limits of ICG strip-test and DC-ELISA were 0.5 and 0.004 ng/mL, respectively, and these methods possessed a cross-reaction to aflatoxins. The results of spiked samples by both methods were coincided with the amount spiked AFB1 and the comparative analyses of 172 real samples by 2 immunoassays and high performance liquid chromatography (HPLC) showed a good agreement. Especially, the ICG strip-test is easier to perform and quicker, but less sensitivity than DC-ELISA. Both methods could analyze a high sample throughput with short time, but the sample throughput of ICG strip-test was better. Therefore, the ICG strip-test can be used as a simple, easy, non-instrumental, and fast screening technique for AFB1 determination.

• Journal of Yeungnam Medical Science
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• 제29권2호
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• pp.83-88
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• 2012

Background: This study was conducted to evaluate the usefulness of the BACTEC MGIT (Mycobacterium Growth Indicator Tube) 960 system for mycobacteria culture and immunochromatographic assay to identify Mycobacterium tuberculosis (MTB) in positive MGIT culture. Methods: Mycobacteria-culture-positive cases were retrospectively analyzed from December 2010 to July 2011. The detection rates and the recovery times of the mycobacteria between the Ogawa media and the MGIT were compared. An immunochromatographic assay (ICA) (SD BIO-LINE) was also performed in the positive MGIT culture for identification, and the results were compared with those of the Ogawa media in the Korea National Tuberculosis Association. Results: Among the 261 patients (M:F, 168:93; mean age, $61.6{\pm}17.16$ yrs), 450 specimens (sputa, 365; bronchial washing, 61; and pleural effusion, 24) were found positive with mycobacteria. Mycobacteria were grown both on the MGIT and Ogawa media in 310 cases (68.9%); only on the MGIT in 115 cases (22.6%); and only on the Ogawa media in 25 cases (5.5%) (p<0.05). The recovery time was $28.2{\pm}8.9$ days in the Ogawa media and $11.1{\pm}5.8$ days in the MGIT (p<0.05). Among the 127 cases from the positive MGIT culture, all 92 cases that were confirmed as MTB cases bythe Korea National Tuberculosis Association were identified as MTB by ICA, with 100% sensitivity. Conclusion: MGIT increases the detection rate and shortens the recovery time of mycobacteria in clinical respiratory specimens, and the TB Ag MPT64 kit using ICA is useful in identifying MTB in a positive MGIT culture.

• 한국어병학회지
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• 제35권2호
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• pp.241-246
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• 2022

White spot syndrome virus (WSSV) is a prevalent and virulent pathogen affecting cultured whiteleg shrimp (Litopenaeus vannamei) in Korea. In this study, seven monoclonal antibodies (mAbs) (10A12, 16C3, 17G4, 21G5, 22C4, 23B6 and 24G6) were produced by using purified WSSV. The reactivity of these mAbs was analysed by Western blot (WB), indirect immunofluorescence (IIF), and lateral flow immunochromatographic assay (LFIA). WB analysis demonstrated that three mAbs (17G4, 22C4, and 23B6) reacted specifically to VP28 with an approximate molecular weight of 24 kDa, mAb 16C3 reacted with approximately 17 kDa. IIF analysis demonstrated specific fluorescence signals on gill tissues of WSSV-infected shrimp, with five mAbs (10A12, 16C3, 22C4, 23B6, and 24G6), pleopods from WSSV-infected shrimp were used for LFIA, where, two mAbs (21G5 and 22C4) exhibited positive reaction. In conclusion, it can be inferred that the mAbs usage and specificity depends on the nature of assay used for diagnosis.

• 대한수의학회지
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• 제45권2호
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• pp.169-177
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• 2005

We developed the one-step strip based on an immunochromatographic (IC) assay for the rapid detection of Listeria spp. Genus-specific monoclonal antibody to flagella of L. monocytogenes was conjugated with 40 nm colloidal gold particles which were prepared in our laboratory. The specificity of the IC strip was tested with pure cultured bacteria. All strains of the genus of Listeria spp. yielded positive reactions and 12 strains of non-Listeria were negative, resulting in a specificity of 100%. L. monocytogenes was artificially inoculated in raw pork macerated with listeria enrichment broth. And then it was 10-fold diluted from $8.7{\times}10^6$ to 8.7 CFU/ml. L. monocytogenes could be detected at a minimum of $8.7{\times}10^5CFU/ml$ before enrichment, $8.7{\times}10^2CFU/ml$ after primary enrichment and 8.7 CFU/ml after secondary enrichment, respectively. These results indicated that the IC strip exhibited high specificity and sensitivity in the detection of Listeria spp.