• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.152-157
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• 2006

The purpose of this study was to evaluate the usefulness of the automated TB-PCR assay for the detection of Mycobacterium tuberculosis. The 807 cases were analyzed with their TB-PCR, AFB smear and culture in bronchial washing fluids, sputum and body fluids samples. The TB-PCR positive of the bronchial washing fluid, sputum and body fluids were 11.3%, 7.3% and 3.6%, respectively, in cases of AFB smear-negative and culture-negative. The sensitivity values of the bronchial washing fluid, sputum and body fluids were 93.3%, 100% and 50%, respectively, according to the culture result. The sensitivity of body fluids was lower than that of the bronchial washing fluid and sputum. The specificity values of the bronchial washing fluid, sputum and body fluids were 83.3%, 89.0% and 95.7%, respectively, according to the culture result. In conclusion, the automated TB-PCR assay proved to be a useful method for the detection of Mycobacterium tuberculosis in the bronchial washing fluid and sputum. But we think that there is still a need for us to study body fluids further.

• Tuberculosis and Respiratory Diseases
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• v.70 no.2
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• pp.125-131
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• 2011

Background: The clinical manifestation of $M.$ $tuberculosis$ infection ranges from asymptomatic latent infection, to focal forms with minimal symptoms and low bacterial burdens, and finally to advanced tuberculosis (TB) with severe symptoms and high bacillary loads. We investigated the diagnostic sensitivity of the whole-blood interferon-${\gamma}$ release assay according to the wide spectrum of clinical phenotypes. Methods: In patients diagnosed with active TB that underwent $QuantiFERON^{(R)}$ (QFT) testing, the QFT results were compared with patients known to be infected with pulmonary tuberculosis (P-TB) and extra-pulmonary TB (EP-TB). In addition, the results of the QFT test were further analyzed according to the radiographic extent of disease in patients with P-TB and the location of disease in patients with EP-TB. Results: There were no statistical differences in the overall distribution of QFT results between 177 patients with P-TB and 84 patients with EP-TB; the positive results of QFT test in patients with P-TB and EP-TB were 70.1% and 64.3%, respectively. Among patients with P-TB, patients with mild extents of disease showed higher frequency of positive results of QFT test than that of patients with severe form (75.2% vs. 57.1%, respectively; p=0.043) mainly due to an increase of indeterminate results in severe P-TB. Patients with TB pleurisy showed lower sensitivity by the QFT test than those with tuberculous lymphadenitis (48.8% vs. 78.8%, respectively; p=0.019). Conclusion: Although QFT test showed similar results between overall patients with P-TB and EP-TB, individual sensitivity was different according to the radiographic extent of disease in P-TB and the location of disease in EP-TB.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.8-13
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• 2014

This study evaluated in vitro cytotoxicity of 5 pesticides, including 2 herbicides, 2 germicides, and an insecticide, as an alternative to the fish acute toxicity test. The in vitro cytotoxicity was tested using a neutral red uptake (NRU) assay with epithelioma papulosum cyprini (EPC) cells that originated from the epidermal tissue of Cyprinus carpio (common carp). An in vivo fish acute toxicity test was conducted according to OECD Test Guideline No. 203 using Aphyocypris chinensis (Chinese bleak), Oryzias latipes (Japanese medaka), and C. carpio. The results showed that the sensitivity of the cell viability assay for the pesticides was similar to the fish acute test in ranking order despite having approximately 10 times less absolute sensitivity. The $r^2$ correlation values were calculated as 0.38 (p = 0.26), 0.76 (p = 0.05) and 0.90 (p = 0.01) for A. chinensis, O. latipes, and C. carpio, respectively. These results suggested that the potential of EPC cell viability assay as an alternative to the fish acute toxicity test due to their good correlation and NRU assay is expected to serve as a useful tool for predicting acute fish lethality for pesticides if further studies with a large set of pesticides are conducted.

• Journal of Veterinary Clinics
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• v.32 no.3
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• pp.219-223
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• 2015

Mycobacterium avium subsp. paratuberculosis (MAP) causes paratuberculosis or Johne's disease, an intestinal granulomatous infection in domestic and wild animals. The study aimed to develop and evaluate a panel of multiplex quantitative real-time polymerase chain reaction (mqPCR) assay for simultaneous detection of three MAP-specific genes (IS900, F57 and ISMAP02 genes). The analytic sensitivity (i.e., limit of detection, expressed as cells per 1 ml) was 150 for IS900, 1500 for F57, and 50 for ISMAP02. The specificity of the method was determined by testing 152 bovine fecal samples. Based on the test, it showed that the assay simultaneously detected the target genes in short period of time and at lower cost compared to laboratory routine tests. The test agreement between the assay and routine test was 94%. The discrepancy in the results was due to samples that were tested positive by the panel but negative by the routine tests, suggesting that the assay has higher sensitivity than the routine tests. In conclusion, the mqPCR assay could be a rapid and accurate testing tool for investigating paratuberculosis or Johne's disease cases in domestic and wild animals.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.269-274
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• 2005

We evaluated the PCR assay and two commercialized PCR kits for the detection of mycoplasma in veterinary via live vaccines. The PCR assay could specifically detect all the tested Mycoplasma spp. and Acholeplasma spp., whereas two commercialized PCR kits did not. Also, the specificity of the PCR assay showed that 4 reference strains and 7 field isolates belonging to avian mycoplasma species could be all detected. The sensitivity of the PCR assay was determined using pure cultured Mycoplasma spp. and Acholeplasma spp. with a range of 1 to 100 colony forming units/ml in 9 CFR Mycoplasma broth. To test the availability of the PCR assay for veterinary live viral vaccines, A. laidlawii was artificially inoculated into the swine transmissible gastroenteritis-rota virus combined vaccine and canine parvovirus vaccine, respectively and the sensitivity of the PCR assay was similar with the result of cultured samples. In this study, the PCR assays could be used as rapid and sensitive methods for the detection of mycoplasma in veterinary live viral vaccines.

• The Korean Journal of Nuclear Medicine
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• v.21 no.2
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• pp.143-150
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• 1987

To assess the analytic performance of immunoradiometric TSH assay (IRMA TSH), assay precision determined by intra and interassay variance, assay accuracy determined by dilution and recovery study, were evaluated by using two commercial kit $(Abott^{(R)}\;and\;Daichi^{(R)})$. Normal range of basal serum TSH and TRH stimulated TSH increment were also determined in 234 healthy subjects (male 110, female 124; age 20-70) and 30 voluteers (male 10, female 20; age 21-26). In addition, basal TSH levels of 70 patients with untreated hyperthyroidism, 50 untreated hypothyroidism, and 60 euthyroidism were measured to assess the clinical utility of IRMA TSH. The detection limit of IRMA TSH was 0.04 mU/l and 0.08 mU/l by Abott Kit and Daichi kit respectively. Using Abott kit, intra assay variance were 2.0, 3.1 and 1.4% in mean TSH concentration 2.4, 31.6 and 98.2 mU/l repectively and interassay variance were 2.0 and 3.2% in mean TSH concentration 2.3 and 31.3 mU/l. Mean recovery rate was 92.5% and dilution study showed nearly straight line. When Daichi kit was used, intrasssay variance were 5.6, 5.2 and 6.2% in mean TSH concentration of 2.4, 31.6 and 98.2 mU/l respectively and interassay variance were 7.1 and 7.4% in mean TSH of 2.3 and 31.3 mU/l. Mean recoveray rate was 89.9%. Normal range of basal TSH and TRH stimulated peak TSH were 0.38-4.02 mU/l and 2.85-30.8 mU/l repectively (95% confidence interval, Abott kit used). Sensitivity and specificity of basal TSH levels for diagnosing hypothyroidism as well as specificity for diagnosing hyperthyroidism were 100% by using both kit. Sensitivity of basal TSH level for diagnosing hyperthyroidism was 100% when TSH levels were measured by Abott kit while that was 80.9% when measured by Daichi kit. These results suggest that IRMA TSH was very precise and accurate method and might be used as a first line test in the evaluation of thyroid function.

• Korean Journal of Veterinary Research
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• v.31 no.2
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• pp.223-228
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• 1991

Most progesterone enzyme immunoassays(EIA) are used liquid-phase double-antibody or single-antibody seperation. These methods consume considerable time and reagents because of the requirements for several washing and centrifugation steps involving the reactants. Because of these several problems, we were prompted to develop an effective enzyme-linked immunosorbent assay(ELISA) system that would be equal or superior to RIA for assay of progesterone. The results were obtained as follows. 1. Cross reaction of the progesterone antiserum with other steroids determined was shown with progesterone(100%), $11{\alpha}$-deoxycorti-costerone(2.271%), but the other steroids were shown below 0.9%. 2. Standard curve for progesterone ELISA was shown available difference according to progesterone concentration from 0 to 1,000pg/ml. 3. The lower limit of sensitivity was 0.2pg/well 4. Progesterone concentration was 1.6ng/ml for before parturition, and that was below 0.5ng/ml for after parturition. This development enzyme-linked immunosorbent assay for progesterone can be detected pregnancy diagnosis in cattle, and also applicable 10 research on physiological function including such as reproductive disorders.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.459-468
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• 2020

This study established a new polymerase spiral reaction (PSR) that combines with reverse transcription reactions for HCV detection targeting 5'UTR gene. To avoid cross-contamination of aerosols, an isothermal amplification tube (IAT), as a separate containment control, was used to judge the result. After optimizing the RT-PSR reaction system, its effectiveness and specificity were tested against 15 different virus strains which included 8 that were HCV positive and 7 as non-HCV controls. The results showed that the RT-PSR assay effectively detected all 8 HCV strains, and no false positives were found among the 7 non-HCV strains. The detection limit of our RT-PSR assay is comparable to the real-time RT-PCR, but is more sensitive than the RT-LAMP. The established RT-PSR assay was further evaluated for detection of HCV in clinical blood samples, and the resulting 80.25% detection rate demonstrated better or similar effectiveness compared to the RT-LAMP (79.63%) and real-time RT-PCR (80.25%). Overall, the results showed that the RT-PSR assay offers high specificity and sensitivity for HCV detection with great potential for screening HCV in clinical blood samples.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.337-342
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• 2007

Conventional methods for pathogen detection and identification are labor-intensive and take days to complete. Biosensors have shown great potential for the rapid detection of foodborne pathogens. Fiber-optic biosensors have been used to rapidly detect pathogens because they can be very sensitive and are simple to operate. However, many fiber-optic biosensors rely on manual sensor handling and the sandwich assay, which require more effort and are less sensitive. To increase the simplicity of operation and detection sensitivity, a binding inhibition assay method for detecting Listeria monocytogenes in food samples was developed using an automated, fiber-optic-based immunosensor: RAPTOR (Research International, Monroe, WA, USA). For the assay, fiber-optic biosensors were developed by the immobilization of Listeria antibodies on polystyrene fiber waveguides through a biotin-avidin reaction. Developed fiber-optic biosensors were incorporated into the RAPTOR to evaluate the detection of L. monocytogenes in frankfurter samples. The binding inhibition method combined with RAPTOR was sensitive enough to detect L. monocytogenes ($5.4{\times}10^7\;CFU/mL$) in a frankfurter sample.

• Journal of Microbiology
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• v.44 no.1
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• pp.92-97
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• 2006

We developed an mPCR assay for the simultaneous detection, in one tube, of Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus and Listeria monocytogenes using species-specific primers. The mPCR employed the E. coli O157:H7 specific primer Stx2A, Salmonella spp. specific primer Its, S. aureus specific primer Cap8A-B and L. monocytogenes specific primer Hly. Amplification with these primers produced products of 553, 312, 405 and 210 bp, respectively. All PCR products were easily detected by agarose gel electrophoresis, and the sequences of the specific amplicons assessed. Potential pathogenic bacteria, in laboratory-prepared and four commercially available kimchi products, were using this mPCR assay, and the amplicons cloned and sequenced. The results correlated exactly with sequences derived for amplicons obtained during preliminry tests with known organisms. The sensitivity of the assay was determined for the purified pathogen DNAs from four strains. The mPCR detected pathogen DNA at concentrations ranging from approximately 0.45 to $0.05\;pM/{\mu}l$. Thus, this mPCR assay may allow for the rapid, reliable and cost-effective identification of four potentially pathogens present in the mixed bacterial communities of commercially available kimchi.