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

• Journal of Food Hygiene and Safety
• /
• v.6 no.3
• /
• pp.111-117
• /
• 1991

We examined to develop the enzyme linked immunosorbent assay (ELISA) for determination of zearalenone in animal feeds. Zearalenone was first converted to 6'-(carboxymethyl) zearalenone oxime(zearalenone oxime) to get a coupling site and then conjugated to bovine serum albumin(BSA) for use as immunogen and to horseradish peroxidase(HRP) for use as enzyme marker. Antibody against zearalenone was obtained after 11 weeks of immunization of rabbit with zearalenone oxime-BSA. Cross reactivity of the antibody with ${\alpha}-zearalanol,\;{\beta}-zearalenol,\;{\alpha}-zearalanol\;and\;{\beta}-zearalanol$ were 168, 46, 26 and 20% respectiviely. A simple procedure was devised for the screening of zearalenone in feeds using ELISA. Feeds samples(5g) were extracted by blending with 25 ml of methanol-phospate butTered saline-dimethylformate(70 : 29 : 1) and the extract was filtered and aqueous filterate analyzed. It took only 1 hours to do whole procedure for the analysis of zearalenone in feeds by the direct competitive ELISA, and detectable limit was 1-100 ppb. Using this procedure, only 4 of 24 feed samples showed positive results with 3.93-7.43 ppb levels.

• Microbiology and Biotechnology Letters
• /
• v.24 no.5
• /
• pp.630-635
• /
• 1996

For a survey of the occurrence of aflatoxin M$_{1}$ (AFM$_{1}$) in domestic cow's milk, we developed an enzyme-linked immunosorbent assay (ELISA) system, and quantitated the toxin in cow's milk. In order to produce specific antibodies AFM, conjugated to bovine serum albumin (AFM$_{1}$-BSA) and Freund's adjuvant were immunized subcutaneously to rabbits. By use of the antiserum showing the highest titer and AFB$_{1}$-HRP conjugate, we established a competitive direct ELISA (cdELISA) for AFM$_{1}$, whose detection limit was 0.003 ppb. The cross-reactivities of the antiserum against aflatoxin M$_{1}$ M$_{2}$, B$_{1}$, B$_{2}$, G$_{1}$, G$_{2}$, B$_{2a}$, and G$_{2a}$, were 100, 29.9, 25.0, 2.7, 13.0, 0.65, 0, and 0%, respectively. When the cdELISA was applied to the cow's milk spiked with AFM$_{1}$ and followed by cleanup with C$_{18}$ cartridge, the mean recovery of the assay was 104% (mean of CV, 6.4%) in the final concentration of 0.01-1 ppb (10-1, 000 ppt). When cow's milk samples gathered from markets and farms were assayed by the cdELISA, the mean concentration and SD of AFM$_{1}$ was 80.4 $\pm$ 55.0 ppt (n=64; range, 5.6-280 ppt).

• Proceedings of the Korean Society of Veterinary Clinics Conference
• /
• 2009.04a
• /
• pp.244-244
• /
• 2009

• Korean Journal of Food Science and Technology
• /
• v.40 no.3
• /
• pp.343-348
• /
• 2008

The ovomucoid (OM) of egg whites is recognized as a major allergen. Here, the allergenicity of OM in egg whites (EW) treated by chemical, enzymatic, and physiological methods were investigated by competitive inhibitory ELISA using human IgE antibody acquired from egg-allergic patients. Enzymatic hydrolysis, irradiation, and succinic anhydride treatments did not reduce the allergenicity of the OM effectively. Allergenicity was reduced to only 1/20 by deglycosylation with trifluoromethanesulfonic acid (TFMS). Heat treatment of the OM at $121^{\circ}C$ for 10 min reduced allergenicity to 1/100. Furthermore, NaOH (over 3%) treatment reduced allergenicity to 1/10,000, and the combinatory treatment of NaOH (over 0.3%) and heat ($70^{\circ}C$, 15 min) reduced it to less than 1/10,000, which was the most effective method. In this study, which analyzed treated EW using ELISA and patient-derived IgE, the OM allergenicity was nearly the same as its antigenicity according to ELISA using rabbit IgG. However, in the case of the TFMS-treated EW, the antigenicity was much lower than the allergenicity. These results suggest that the allergenicity of OM is slightly different from its antigenicity.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2002.11b
• /
• pp.185-185
• /
• 2002

A murine local lymph node assay (LLNA) has been developed as an alternative test to guinea pig maximization test. The disadvantage of LLNA is the need for the use of radioactive material. In this study, we aimed to investigate the development of non-radio isotopic endpoint for local lymph node assay in Balb/c mice using Enzyme-linked immunosorbent assay (ELISA) based on Bromodeoxyuridine (BrdU) incorporation.(omitted)

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.176-176
• /
• 1996

축산식품중에 잔류하고 있는 sulfamethazine을 검출하기 위하여 sulfamethazine에 대한 단클론항체를 생산하고 이를 이용하여 효소면역측정법을 개발하였다. 면역원은 sulfamethazine에 KLH를 그리고 흡착항원은 BSA를 glutaraldehyde법으로 결합시켰다. 면역원으로 Balb/c mouse를 면역시킨 다음 비장 형질세포률 얻어 myeloma cell과 융합하여 융합잡종세포를 만들었다. Sulfamethazine에 대한 항체를 분비하는 융합잡종세포를 단계회석법과 ELISA를 이용하여 cloning하여 D2, A9, B8, Bl 클론을 얻었다. 이들 클론에서 얻어진 단클론항체를 사용하여 indirect competitive ELISA를 실시하여 표준곡선을 작성하여 본 결과 농도의존성 곡선을 얻을 수 있었다. 4클론중에서 A9 클론을 사용하여 다른 유사한 sulfonamide듣과 p-aminobenzoic acid와 교차반응을 조사한 결과 sulfamerazine에 12.5%의 교차반응을 보였으나 다른 설파제에 대해서는 교차 반응을 보이지 않았다.

• Tuberculosis and Respiratory Diseases
• /
• v.59 no.1
• /
• pp.47-52
• /
• 2005

Background : Chlamydia pneumoniae is a clinically important pathogen, the diagnosis of such infection being based mainly on serology. Microimmunofluorescence (MIF) is the current standard diagnostic method, but is subjective and time-consuming, so the authors tested the serology of chronic cough patients using an EILSA method for the Chlamydial antibody, which is a more objective method, and compared the results with those of the standard method. Method : Thirty-five patients, who visited Kangwon National University Hospital between August 2003 and July 2004, were evaluated. A MIF and ELISA tests were used to determine C. pneumoniae antibody titers. Nasopharyngeal aspirates were examined by polymerase chain reaction (PCR). The Spearman rank correlation test was used for data analysis. Results : Sensitivities of ELISA for IgG, IgA and IgM, as judged by MIF, were 84.0, 84.0 and 40.0% and the specificities were 60.0, 60.0 and 96.7%, respectively. Three patients were Chlamydia PCR positive. Conclusion : ELISA can be a useful tool for studying the seroprevalence of Chlamydia pneumoniae. However, further studies will be required prior to its clinical use.

• Korean Journal of Poultry Science
• /
• v.18 no.3
• /
• pp.183-196
• /
• 1991

In order to establish ELISA method to detect antibody against IBV various factors involved were examined. Antigen was prepared from Massachusetts type IBV which is known to be one of serotypes distributed most widely. The virus was grown in embryonated SPF chicken eggs. Allantoic fluid harvested was processed to ultracentrifugation and sucrose density gradient centrifugation to produce a purified antigen The antisera selected from the field samples based on hemagglutination inhibition test were used as the standard positive and negative sera for this study and the results obtained were summarized as follows. 1 , It was found that ELISA test was satisfactory when the purified antigen was coated on the plate in the amount of about 40ng protein per well. In case of the phospholipase treated hemagglutinating antigen it gave satisfactory results when the each well wns coated with 1.2 to 2.5 hemagglutinating unit which was equivalent to 40 to 90ng of protein. 2. There was no significant difference in the ratio of optical density of positive to that of negative serum whether the coated antigen was held for 1 hour at 37$^{\circ}C$ or it was held overnight at 4$^{\circ}C$. The coated antigen could be kept in dried state without change of antigenecity for at least one month of experimental period at 4$^{\circ}C$. 3. There was a big variation in the optical density and P/N values depending on the maker of the plates and on the plate of the same maker. 4. It was found that background optical density was negligible when serum was diluted more than 1：50 and serum dilution of 1：100 appeared to be appropriate as a routine test dilution to screen the antibody. 5. Optical density was fairly constant 15 minutes afterward from the time substrate was treated and during the 4 hours after stopper was treated. 6. There was a low correlation(r＝0.42) between ELISA and HI test. However, when 74serum samples were tested for the IBV antibody, 98.7% were found to be positive by both tests in which titers of 2$^{6}$ or more by HI test and P/N values of 1.4 or more by ELISA were considered to be positive, 7 Day-old IBV vaccinated chickens shows a similar antibody decay and rising pattern until 8 weeks of age by the two tests, ELISA and HI.

• Korean Journal of Food Science and Technology
• /
• v.44 no.1
• /
• pp.1-7
• /
• 2012

There have been few studies related to ELISA for mackerel. In this study we developed a sandwich ELISA for mackerel in processed foods using rabbit polyclonal antibodies against mackerel parvalbumin, the major allergen of mackerel and heat-stable protein. The parvalbumin was purified by ammonium sulfate precipitation and Sephadex G-50 column chromatography. From the standard ELISA curves, the detection limit of parvalbumin was 3 ng/mL and the detection range of mackerel was 5-5,000 ${mu}g/mL$. We further investigated the cross-reactivity of the antibodies toward mackerel, mackerel pike, salmon, flatfish, armorclad rockfish, cod fish, squid, shrimp, blue crab, and lobster. The antibodies were specific for mackerel only. The mean assay recoveries in cooked cream soup, baby food, sausage, and sauce spiked with 0.01 to 0.3% mackerel were 104, 101, 54, and 0%, respectively. In sample tests of 16 commercial items, the qualitative coincidence ratio of assay result and indication was 75%.