• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.503-515
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• 1989

Critical parameters affecting sensitivity and specificity of an enzyme-linked immunosorbent assay(ELISA) for detection of antibodies to avian infections bronchitis virus(IBV) were standardized. By adopting the optimized conditions an equation calculating ELISA antibody titers from the observations at single serum dilution was formulated. The purified antigen of IBV Mass-41 strain was dispensed into polystyrene microplate wells at a concentration of 300ng per well($100{\mu}l$) and the plates were coated by completey drying at $37^{\circ}C$. Diluted chicken serum and horseradish peroxidase conjugated goat anti-chicken IgG were added in order in $100{\mu}l$ volumes per well and allowed to react for 30 minutes each at room temperature. Just before use and after each reaction the plates were washed three times with distilled water. Finally o-phenylenediamine solution was added as an enzyme substrate. After incubation for another 15 minutes at room temperature absorbances were read at 492nm. Hyperimmune serum against Mass-41 strain was used as internal reference positive(IRP) serum. After repeated titration of IRP and negative serum, a constant titer of IRP was determined. Serum titrations were carried out for various sample sera together with IRP and negative sera and the observed titers of sample sera were corrected by reflecting the ratio between observed and constant titers of IRP serum. These corrected titers of the sample sera were plotted against sample/positive(S/P) OD ratios. All the OD's measured in the serum titrations were also corrected by substracting negative serum OD. The following equation was formulated from the above data; $Log_{10}$ ELISA titer=$5.568({\log}_{10}S/P)+4.161$ Thus it was possible to calculate ELISA titer by measuring absorbance at 1/400 single serum dilution. Titer measured by cross ELISA tests employing Mass-41 strain and three local IBV isolates were similar. These results suggest that the ELISA tests standardized in this study can be used for evaluating not only vaccinal immunity but also for infection status against fields IBV's.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1655-1658
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• 2014

Objective: To find a more appropriate alternative to D-dimer cutoff value for the diagnosis of deep vein thrombosis (DVT) in cancer patients. Methods: A total of 711 cancer patients with symptoms suspicious of DVT were included in the study. D-dimer levels were assessed using ELISA. All patients were subjected to imaging procedures. Results: Among 711 patients with cancer, 466 (65.5%) were females and 245 (34.5%) were males, with an average age of $57.3{\pm}13.23$ years. The mean age in the DVT group was significantly higher than in the non-DVT group (P<0.05). The D-dimer levels of the DVT group were significantly higher than those of the non-DVT group (P<0.05). The incidence rate of DVT varied significantly according to cancer type (P<0.05). Increasing age and lung cancer were significantly correlated with D-dimer levels (P<0.05), and a one-year increase in age was associated with a 14.28 ng/ml increase in the D-dimer value. The optimal cutoff point for D-dimer was found to be 981 ng/ml, with a sensitivity of 86.4%, specificity of 79.4%, and accuracy of 82.6%. If the D-dimer cutoff point was set to 981ng/ml, the specificity would increase from 61.8% to 85.5% without loss of sensitivity in patients aged 40 years or younger. In patients aged more than 40 years, the new cutoff almost doubled the specificity with slightly reduced sensitivity. Conclusion: In cancer patients, a new cutoff value of 981 ng/ml effectively improved the exclusion of DVT, especially for patients aged more than 40 years.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.81-85
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• 2013

Background: Early diagnosis of carcinoma of bladder remains a challenge. Survivin, a member of the inhibitor of apoptosis (IAP) protein family, is frequently activated in bladder carcinoma. The objective of this study was to investigate urinary survivin as a marker for diagnosis of urinary bladder. Materials and Methods: We examined urinary survivin concentration in 28 healthy individuals, 46 positive controls and 117 cases of histologically proven TCC prior to transurethral resection, using ELISA, and compared values with findings for urinary cytology. Results: Survivin was found to be significantly higher in the cancer group (P<0.05). A cut off value of 17.7 pg/ml was proposed, with an approximate sensitivity of 82.9% and specificity of 81.1% (P<0.0001), whereas urine cytology had a sensitivity of 66.7% and a specificity of 96.0%. Conclusions: Urinary survivin can be used as a non-invasive diagnostic biomarker for TCC bladder, both for primary and recurrent disease.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.51-57
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• 2001

A procedure for extraction and purification of 8 kDa antigen of Brucella abortus RB51 was developed. Bacteria heat inactivated at $60^{\circ}C$, 30 min was extracted by 1% sarcosine and followed by fluid pressure liquid gel filtration chromatography of 2 series, Superose 12 HR 10/30 and Sephacryl S-100. There was produced $71.46{\mu}g/g$(wet) of 8 kDa antigen, and it resisted 1% trypsin, solved 1% triton X-100 higher than distilled water and inactivated 0.1% proteinase K. These results show that 8 kDa antigen may be a lipoprotein existed cell surface of B. abortus RB51. Also, we developed ELISA using purified 8 kDa surface antigen of Brucella abortus RB51 strain, its specificity and sensitivity was 95.0%, 98.6%, respectively. As compared with dot-blot assay using whole cell and ELISA using 8 kDa antigen, its correlation was 93.5%.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.849-855
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• 2012

Plant growth-promoting rhizobacteria (PGPR) pseudomonads have a large number of lipopolysaccharides on the cell surface, which induces immune responses. Cd-resistant PGPR prevalent at the Cd-affected sites under biophytostabilization was monitored. Transmissiom electron microscopy was used to the study the behavior of tolerance of PGPR to cadmium level and its effect on pseudomonad strains (Z9, S2, KNP2, CRPF, and NBRI). An immunosensor was developed by immobilizing antibody (anti-Z9 or anti-S2) against selected PGPR on a piezoelectric quartz crystal microbalance (QCM). Immunosensors were found to supplement the inherent specificity of antigen-antibody reactions with the high sensitivity of a physical transducer. On comparison of the efficiency of detection with ELISA, the spectrophotometric technique, the developed immunosensor was found to be more sensitive, fast, and reliable even after regeneration for several times. Thus, the immunosensor may be used for future detection of PGPR strains after automation of the screening process.

• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.517-523
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• 1989

This study was undertaken to establish reliable diagnostic-procedures for the microbiological monitoring of laboratory animals. Murine(mice and rats) antibodies against hemagglutinating virus of Japan(HVJ), mouse hepatitis virus(MHV) and Mycoplasma pulmonis(Mp) were detected sensitively and specifically in experimentally and naturally infected animals' sera by an indirect enzyme-linked immunosorbent assay(ELISA), using urease conjugated antimurine immunoglobulin. The sensitivity and specificity of the complement fixation test which has been apllied widely for serodiagnosis of HVJ, MHV and Mp infections were apparently lower than those of ELISA. From these results, the ELISA was found to be available for the serodiagnosis of HVJ, MHV and Mp infections in mice and rats.

• Parasites, Hosts and Diseases
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• v.57 no.1
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• pp.61-67
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• 2019

Cystic echinococcosis (CE) in sheep is a hazardous zoonotic parasitic disease that is caused by Echinococcus granulosus (Eg). At present, serological test is an important diagnostic method for Eg infection in domestic animals. Here, a fusion protein Eg mefAg-1 harboring 8 dominant B-cell epitopes of Eg such as antigen B, tetraspanin 1, tetraspanin 6, reticulon and Eg95 was produced in E. coli and evaluated for CE in sheep by indirect ELISA. Eg mefAg-1 showed in ELISA a high sensitivity (93.41%) and specificity (99.31%), with a coincidence rate of 97.02%. Overall, it is suggested that the Eg mefAg-1 could be a potential antigen candidate for CE serodiagnosis in sheep.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.255-260
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• 1998

Since bovine leukosis caused considerable economic loss to the dairy industry, seroepidemiologi-cal survey on bovine leukosis was carried out for the dairy herds in Kyunggi province. 1. When compared the results of immunodifussion test with those of enzyme-linked immunosorbent assay(ELISA) for 94 dairy herds sera, the relationship between the immunodifussion test and ELISA were showen high corresponding rate with sensitivity(97.5%) and specificity(92.6%). 2. In immunodiffusion test for bovine leukosis virus (BLV) antibody in 570 dairy cattle from 30 herds, mean positive rate for BLV antibody was 28.2%. The positive rate by districts were 16.5% in central, 35.4% in east, 17.3% in west, 29.1% in south, 31.6% in north, 43.7% in northeast. 3. When the results of serological studies was analyzed by age groups, the number of positive was increased gradually with the advanced in age of herds. The highest positive rate was found in the age over 6 years. 4. Of 30 dairy herds examined, 5 herds(16.7%) have no reactions against BLV antigen while 15 herds (50%) showed the range of 1∼5 positive cattle and 5 herds(16.7%), the rang of over 11 positive cattle.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.31-36
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• 2017

Japanese encephalitis (JE) is an important zoonosis caused by the mosquito-transmitted JE virus (JEV), which is a causative agent of reproductive failure in pregnant sows. Detection of JEV antibodies in swine is performed by hemagglutination inhibition (HI), virus neutralization (VN), and the plaque reduction neutralization test (PRNT). The most stringent PRNT is the 90% endpoint PRNT ($PRNT_{90}$). These conventional assays are difficult to carry out in diagnostic laboratories with insufficient instruments or cell culture systems. An alternative assay that is easily conducted and time efficient is required. In this study, we improved the indirect enzyme-linked immunosorbent assay (I-ELISA) with clarified antigen for the detection of JEV antibodies. The I-ELISA results obtained from 175 swine serum samples were compared with HI, VN, and $PRNT_{90}$ results. The sensitivity of I-ELISA was 91.8%, 95.0%, and 94.7% compared with HI, VN, and $PRNT_{90}$ results, respectively. The specificity of I-ELISA was 92.2%, 94.7%, and 94.7% compared with HI, VN, and $PRNT_{90}$ results, respectively. Moreover, the I-ELISA results were significantly correlated with the HI (r = 0.93), VN (r = 0.95), and $PRNT_{90}$ (r = 0.92) results. These results suggest that the improved I-ELISA is useful for serosurveillance of JEV in swine.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.59-66
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• 1992

An enzyme immunoassay(EIA) was developed for the analysis of insecticide endosulfan and its degradation products. The sensitivity and specificity of the antibody produced were examined. Optimal conditions in the ELISA system for residue analysis were also discussed. A mixed suspension of endosulfan-hemocyanin conjugate(ES-KLH) 1.1 mg/ml and Freund's adjuvant was injected subcutaneously to white rabbits and then collected antisera were tested for titers by indirect ELISA(1/24,000). Because of difficulties in the synthesis of endosulfan peroxidase conjugate, amine derivative of endosulfan-diol was synthesized and it showed 40% of conjugate yields(2mg/ml of conjugate). the highest sensitivity obtained enzyme-conjugate was a concentration of 200ng/ml. The detection limit of endosulfan in ELISA system was 5 ppb on the standard curve. In application of ELISA for residue analysis, the recoveries were really 100% both in the spiked soil and apple sample regardless of endosulfan concentration treated. On the other hand, chlorinated hydrocarbons of similar structure with endosulfan showed low cross-reactivity$(2.2%{\sim}29.2%).$