• Korean Journal of Veterinary Service
• /
• v.25 no.3
• /
• pp.237-243
• /
• 2002

The study was performed to investigate the antibody distributions of 4 swine respiratory disease including M hyopneumoniae, P multocida, A pleuropneumoniae serotype 2 and 5 in Daegu area by enzyme-linked immunosorbent assay(ELISA). 1. The overall sero-positive rates were 55.6% in June, 48.0% in August, 51.3% in October and 25.4% in November. 2. The positive reaction rates to M hyopneumoniae, P multocida, A pleuropneumoniae serotype 2 and 5 were found to be 50.0%, 36.5%, 55.0%, and 42.0% respectively. 3. The antibody titers were distributed on range 20～80 in M hyopneumoniae, 20～80 in P multocida, 160～640, 20～80 in A pleuropneumoniae serotype 2 and 5.

• Toxicological Research
• /
• v.27 no.2
• /
• pp.125-131
• /
• 2011

Through the present study, we produced a monoclonal antibody against aflatoxin B1 (AFB1) using AFB1-carboxymethoxylamine BSA conjugates. One clone showing high binding ability was selected and it was applied to develop a direct competitive ELISA system. The epitope densities of AFB1-CMO against BSA and KLH were about 1 : 6 and 1 : 545, respectively. The monoclonal antibody (mAb) from cloned hybridoma cell was the IgG1 subclass with ${\lambda}$-type light chains. The $IC_{50}s$ of the monoclonal antibody developed for AFB1, AFB2, AFG1 and AFG2 were 4.36, 7.22, 6.61 and 29.41 ng/ml, respectively, based on the AFB1-KLH coated ELISA system and 15.28, 26.62, 32.75 and 56.67 ng/ml, respectively, based on the mAb coated ELISA. Cross-relativities of mAb to AFB1 for AFB2, AFG1 and AFG2 were 60.47, 65.97 and 14.83% in the AFB1-KLH coated ELISA, and 59.41, 46.66 and 26.97% in the mAb coated ELISA, respectively. Quantitative calculations for AFB1 from the AFB1-Ab ELISA and AFB1-Ag ELISA ranged from 0.25 to 25 ng/ml ($R^2$ > 0.99) and from 1 to 100 ng/ml ($R^2$ > 0.99), respectively. The intra- and inter-assay precision CVs were < 10% in both ELISA assay, representing good reproducibility of developed assay. Recoveries ranged from 79.18 to 91.27%, CVs ranged from 3.21 to 7.97% after spiking AFB1 at concentrations ranging from 5 to 50 ng/ml and following by extraction with 70% methanol solution in the Ab-coated ELISA. In conclusion, we produced a group specific mAb against aflatoxins and developed two direct competitive ELISAs for the detection of AFB1 in feeds based on a monoclonal antibody developed.

• Parasites, Hosts and Diseases
• /
• v.28 no.4
• /
• pp.207-212
• /
• 1990

Enzyme-linked immunosorbent assay(ELISA) of paragonimiasis iloktsuenensis rat sera was performed using crude antigens of Paragonimus iloktsuenensis(PIA), P. westermani (PWA) and Clonorchis sinensis(CSA). Three crude antigens(PIA, PWA, CSA) were prepared to saline homogenated supernatants of whole adult worms. Infected rat sera were obtained biweekly from the albino rats fed 50∼.80 metacercariae of P. iloktsuenensis through gastric catheter. Experimental groups were divided into 4 groups: GI(controls), GII, GIII and GIV according to 1∼7 worms as GII, 10∼19 worms as GIII and 22∼40 worms as GIV, respectively, In ELISA, the mean OD values of each group for the homologous antigen(PIA) were increased significantly compared to the control sera at the 4th week of infection. With the progress of duration of infection, the mean OD values of infected sera of GII & GIV continuously increased up to the 12th week(last week), but in GIII the mean OD value increased until the loth week. No significance was noted among the infection dose groups (GII, GIII and GIV), after the 6th week of infection. Also, the OD values of all infected rats did not show any Proportional relytionships to the number of worms recovered. In brief, the antibody productivity of individual rats were strongly different. The rat sera infected with p. iloktsuenensis cross-reacted with those infected with P. westermani or C. sinensis, as identified by OD values.

• Journal of Food Hygiene and Safety
• /
• v.18 no.3
• /
• pp.95-100
• /
• 2003

Competitive direct enzyme-linked immunosorbent assay(cdELISA) of aflatoxin $B_1$ ($AFB_1$) in deonjang(Korean-style soybean paste) and kochujang(fermented hot peppersoybean paste) and the level of $AFB_1$ in modern or traditional style deonjang and gochujang, produced in Korea, was surveyed by cdELISA. From the standard curve of the cdELISA, the detection limit of $AFB_1$ was 0.2 ng/m/. The average recovery of $AFB_1$ was 71.5% in the range of 1~100 ng/g after spiking $AFB_1$ into deonjang and it means that it could be possible to detect the $AFB_1$ in these range by the cdELISA in deonjang. Among the 30 kochujangs tested, no $AFB_1$ was detected in kochujangs. Among the 30 deonjangs, $AFB_1$ was detected in 6 ones in the range of 1.0~6.0 ng/g. The occurrence of $AFB_1$ in deonjang and kochujang tested in this study was less than the Korea Standard and Specification of aflatoxin in foods (10 ppb).

• BMB Reports
• /
• v.34 no.1
• /
• pp.80-84
• /
• 2001

The human papillomavirus E7 protein can form a specific complex with a retinoblastoma tumor suppressor gene product (p105-Rb) that results in the release of the E2F transcription factor, which is critical for the growth-deregulation and transforming properties of the viral E7 oncoprotein. In an attempt to apply interaction between the E7 oncoprotein and a target cellular protein Rb for an in vitro screening system for drugs against human papillomavirus infection, we primarily investigated the E7Rb binding through a pull down assay and enzyme-linked immunosorbent assay. The pull down assay showed that both glutathione S-transferase-tagged E7 and His-tagged E7 immobilized on resins specifically produced complexes with bacterially expressed Rb in a dose-dependent manner, as determined by immunoblot analyses. This result coincided with that of an enzyme-linked immunosorbent assay, which is a useful system for the mass screening of potential drugs. Taken together, this screening system (based on the interaction between E7 and Rb) can be a promising system in the development of drugs against cervical cancers caused by human papillomavirus infection.

• Korean Journal of Food Science and Technology
• /
• v.47 no.3
• /
• pp.401-404
• /
• 2015

A sandwich ELISA (sELISA) to detect pork in processed foods was developed using goat anti-pig IgG antibodies. From the sELISA standard curve, the detection range of pork was $3-1,000{\mu}g/mL$. The cross-reactivity between the pig IgG antibodies, pork, and other meats (beef, chicken, fish, and crustaceas) was 100, 0.18, and 0%, respectively. When pork was heated for 10 min, the mean assay recoveries of pig-IgG were 79-32% at $60-70^{\circ}C$ and less than 0.11% at $80^{\circ}C$ or higher. When pork was spiked into cream soup, weaning food, fish paste, and sauce, the mean assay recoveries were 8.8, 45, 36, and 39%, respectively. In 12 commercial processed foods, the assay results coincided qualitatively with the food labels on the packages.

• Korean Journal Plant Pathology
• /
• v.3 no.2
• /
• pp.108-113
• /
• 1987

Rice black-streaked dwarf virus(RBSDV) was purified from infected maize leaves. Antiserum against RBSDV was prepared for virus detection by enzyme-linked immunosorbent assay(ELISA). In detection of RBSDV by ELISA, effective dilution range of antiserum extracted in RBSDV-containing host plants and insect vectors was from 320 to 2,560 times in rice plant, 320 to 5,120 in maize plant, and 160 to 2,560 times in insect vector, Laodelphax striatellus F, respectively. The percentage of viruliferous vector in overwintered nymphs of Laodelphax striatellus determined by ELISA were 3.0 in Milyang, 2.3 in Chilgok, and 3.7 in Sunsan area. Dead insect vector which could not be tested for vims infection by conventional rice seedling inoculation test could be tested by ELISA. One hundred plants of rice and maize were randomly sampled in the field and tested whether or not they were infected with RBSDV. In rice plants, 4 out of 98 plants turned out to be infected with RBSDV by ELISA. In maize plant, 3 out of 92 plants which were excepted 8 plants to be appeared symptom already were infected. As a result, ELISA could be detected even in case of symptomless plants at early stage of viral infection.

• Korean Journal of Veterinary Research
• /
• v.31 no.4
• /
• pp.491-500
• /
• 1991

This study was conducted to detect the serum antibodies in the experimentally toxoplasma infected dogs and street dogs by use the of an enzyme-linked immunosorbent assay (ELISA). And this test was performed on the polystylene microplate by coating with the tachyzoites soluble antigen of T gondii (RH strain), incubated with sera diluted then, added with HPO-conjugated rabbit anti-dog IgG and o-phenylenediamine used as a substrate. Tachyzoites of T gondii harvested from mouse peritoneal cavity were purified by 30, 40 and 50% Percoll density gradient centrifugation and used as the source of antigen. The results obtained were summarized as follows; 1. The highest ratio of positive to negative (P/N ratio) was obtained at the level of $l{\mu}g/ml$ protein concentration of antigen with the 1/4000 dilution of the conjugate measured by checker-board titration. It was regarded as the optimum concentration of the antigen and conjugate. 2. Cut-off value in this IgG ELISA was 0.375 that was determined by mean absorbance (at 492nm) of IFA negative serum added with the dauble value of the standard deviation $(mean{\pm}2S.D.)$. 3. Serum ELISA IgG antibodies to T gondii in the exyerimentally infected dogs were detected firstly at the Week 3 after inoculation and the highest titer was recognized at the Week 4, 5 and 6 after inoculation. 4. Stability of the antigen absorbed in the microplates that were preserved at $4^{\circ}C$ and $-25^{\circ}C$ separately were prolonged up to 3 weeks and 10 weeks at $4^{\circ}C$ and $-25^{\circ}C$, respectively. However the reproducibility was not reliable after the preservation of 4 weeks and longer. 5. Positive rate of the specific antibodies in 312 test sera was 28.5% and there was no significant differences between the male (27.8%) and female (29.5%), respectively. 6. The IgG ELISA was proved to be a specific procedure for the detection of antibodies to canine toxoplasma infection and also evaluated as a screening test for the large scale of test samples in laboratory.

• Korean Journal of Veterinary Service
• /
• v.42 no.1
• /
• pp.9-15
• /
• 2019

Transmissible gastroenteritis (TGE) is a disease confined to pigs of all ages, and can be a significant cause of economic loss in breeding herds, primarily because of the very high piglet mortality. The causative agent is a coronavirus, an enveloped positive strand RNA virus and closely related but non-enteropathogenic porcine respiratory coronavirus (PRCV). Although the TGEV has declined with its innocent relative, PRCV, further genome changes could not be excluded. Therefore, the herd-level immunity against this virus is important for the prevention of disease and should be carefully monitored. The aim of this study is to develop monoclonal antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) which can rapidly and accurately determine a large numbers of serum samples for surveillance purpose, and to compare the ELISA with a TGEV-specific serum neutralization test. The MAC-ELISA was sufficiently achieved, and the comparison with the virus-specific serum neutralization assays for 713 sera from pig farms showed a high correlation ($r^2=0.812$, P<0.001). The specificity and sensitivity of MAC-ELISA for the serum neutralization test 91.9% and 91.6%, respectively, which means that the antibody detected by the MAC-ELISA could be said to be protective antibodies. In conclusion, the developed MAC-ELISA would be very helpful in evaluating protective antibodies against TGEV.

• Korean Journal Plant Pathology
• /
• v.14 no.1
• /
• pp.83-91
• /
• 1998

Gladioli (Gladiolus hybridus) showing flower colour breaking leaf mosaics, notched leaf, and dwarfing or lack of visible symptoms were collected from gladioli growing areas in Taegu and Kyungpook province, Korea. The three viruses isolated from the naturally infected gladioli were identified as broad bean wilt virus (BBWV), cucumber mosaic virus (CMV), and tobacco rattle virus (TRV) by their host range, immunosorbent electron microscopy (ISEM), enzyme-linked immunosorbent assay (ELISA), direct tissue blotting immunoassay (DTBIA), and intracellural symptoms. By DTBIA and ISEM, TRV was detected in gladiolus showing notched leaf, while CMV was frequently detected in gladioli with dwarfing, color breaking and malformation of flowers. BBWV was also often detected in many symptomless gladiolus plants, but TRV was detected in notched-leaf of gladiolus. Electron microcopic examination of negatively stained preparations showed that BBWV and CMV are spherical particles of 28 nm and 30 nm in diameter, and TRV is rigid rod-shaped particles of 40∼200 nm in length. The rigid rodshaped virus particles reacted positively with TRV antiserum in ISEM and DTBIA, respectively.