• Journal of Veterinary Clinics
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• v.27 no.4
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• pp.402-406
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• 2010

Bovine leukemia virus (BLV) is a delta-retrovirus which causes chronic lymphocytosis in cattle. BLV infections have been divided into two groups such as enzootic bovine leukosis (EBL) and sporadic bovine leukosis (SBL) according to the clinical symptoms in infected cattle. The conventional detection method of BLV was hematological procedure which is determining lymphocytosis in the suspected animals. Recently several sensitive methods were developed to detect antibody to BLV and nucleic acid of the BLV from infected cattle. In this study we have compared the difference of positive rates between agar gel immunodiffusion (AGID) and enzyme linked immunosorbent assay (ELISA) which are using for BLV antibody detection methods. The positive detection rate of ELISA test was 7.4% greater than the positive rate of AGID. The discrepancy of the positive rate between ELISA and AGID were showed in the group of age over one year old to under three year old group. The result from each test agreed very well in the group of over 5 year old cattles. The serological test is very useful method to select the infected cattle for the eradication or control of the disease in the infected herd. But it has a limit by interference of the maternal antibody from the cow of under 6 month old. This study shows that 16.2% of these ages group showed BLV gene positive by polymerase chain reaction (PCR) method. The result suggests that ELISA test need to be used with PCR to clarify misinterpretation of positive animals by antibody response due to the natural infection from maternally derived antibody in calves of under 6 months old.

• Korean Journal of Veterinary Service
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• v.43 no.4
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• pp.237-244
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• 2020

Porcine transmissible gastroenteritis (TGE) has been a significant cause of economic losses in pig farming industry since 1950s. Although transmissible gastroenteritis virus (TGEV) has declined in recent years, it should not be excluded because of its characteristics; the frequency of gene mutation, the mortality in piglets, and the possibility for sudden incidence. Therefore, the herd-level monitoring of the virus is important to prevent further circulation of TGE. The aim of this study is to develop a large-scale sandwich enzyme-linked immunosorbent assay (ELISA) with high specificity to rapidly detect TGEV in feces by using monoclonal antibodies (Mabs). The TGEV specific Mabs were produced in hybridoma cells. Among the Mabs belonged to the IgG class developed by this study, the final selected 8H6, 1B7, 4G3, and 1F8 were identified to have the neutralization ability against TGEV. The sandwich ELISA was established using 8H6 as a reporter antibody and 1B7 and the reported 5C8 as a capture antibody. The developed sandwich ELISA was able to distinguish TGEV from other pathogenic diarrheal agents (porcine rotavirus, porcine reovirus, porcine epidemic diarrhea virus (PEDV), E. coli, and C. perfringens) in tissue culture as well as fecal samples. And the detection rate of TGEV in feces was 80% compared with RT-PCR. The results suggested that the developed sandwich ELISA may be useful in the herd-level monitoring for effective preventive measures due to the early diagnosis of TGEV using a large amount of samples.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.727-727
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• 2005

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.397-403
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• 1992

This study was carried out for the development of assay method to quantify the soy protein content in meat homogenate, emulsion-type sausage and commercial meat products by Enzyme-linked Immunosorbent Assay(ELISA). The standard antigen was extracted before and after heat treatment. It was observed that the degree of reaction was not varied significantly according to the heating temperature. The recovery rate in meat homogenate and emulsion-type sausage was not varied significantly according to the heating temperature. The reaction was not interfered with fat and spices of the samples. Samples with 10% soy protein showed lower correlation than those with 2% and 5% soy protein. The recovery rate in commercial meat products showed difference individually. The correlation of some products with raw vegetable and wheat starch was relatively low.

• BMB Reports
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• v.30 no.6
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• pp.390-396
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• 1997

A sandwich-type enzyme-linked immunosorbent assay (ELISA) for the quantification of human apolipoprotein A-I (apoA-I) was developed using monoclonal antibodies. For this assay, we used three monoclonal antibodies to trap and detect apo A-I. HDAI16 and HDA15 monoclonal antibodies were used for trapping apoA-I and HDAI8 monoclonal antibody was for detecting apoA-I. These three monoclonal antibodies were produced by immunizing mice with high density lipoprotein (HDL) isolated from human plasma. By immunoblot analysis, these three monoclonal antibodies were specific to apoA-I and showed no cross-reactivities with other plasma proteins. The results of competition assays for epitope cross-reactivity test also verified that these monoclonal antibodies identified separate and distinct epitopes on HDL and apoA-I. Affinity constants of monoclonal antibodies were measured by ELISA. Their association constants ranged from $10^7$ to $10^8$ $M^{-1}$. For this assay, pure apoA-I was isolated by affinity chromatography using monoclonal antibodies. In this sandwich assay, the amount of HRP-labeled HDAI8 bound to apoA-I trapped by HDAI16 and HDAI5 was proportional to apoA-I concentration in the range of 0 to 500ng/ml. ApoA-I concentration in plasma was calculated from the linear regression equation of standard curve. The precision and reliability of the assays are reflected in the low intra-and interassay coefficients of variation that averaged 3.25% and 4.30%, respectively. This assay is sensitive, simple, reproducible, convenient in incubation interval, and does not use radioisotope: thus it can be widely applied in clinical laboratories.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.59-65
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• 1996

For easy and rapid screening of hemorrhagic fever with renal syndrome (HFRS) without any laboratory equipment, dot blot enzyme immunoassay was developed and tried to detect anti-hantavirus antibodies. The nucleocapsid protein of Hantaan virus was isolated by affinity chromatography and used for making the dot strip. 28 of 29 Hantaan virus infected sera showed positive signals and 21 of 22 HFRS negative sera showed no positive signals. Anti-Seoul virus monoclonal antibody also exibited positive signal but the intensity of colorization was approximately 5 fold less than that of anti-Hantaan monoclonal antibody. The sensitivity of dot blot assay was equal or superior to indirect immunofluorescent assay (IFA) or ELISA test. Overall, the screening results with dot blot assay showed 92.2 % of concordance with IFA or ELISA test. This results suggests that dot blot assay could be applied a tool for easy and rapid screening of HFRS.

• Journal of Food Hygiene and Safety
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• v.4 no.3
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• pp.171-176
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• 1989

A rapid, simple method of ELISA was applied for the determination of aflatoxin BI in cereals from Y oungnam districts. Antibodies obtained cross reacted with aflatoxin B2 and to a less extent with other aflatoxin BI analogs. Response range for a typical standard curve was between I and 100 ppb. Fewer interference by spiked methanol-PBSdimethylformamide extracts ofrice was evidenced. Contents of aflatoxin BI from rice (65) and barley (116) were determined by competitive direct enzyme- linked immunosorbent assay as follows. Three out of 65 rices samples were positive. Rice samples of R-IS, R-30, and R-59 represent the aflatoxin B1 levels of $7.5\;\mu\textrm{g}.kg,\;6.0\;\mu\textrm{g}/kg,\;3.5\;\mu\textrm{g}/kg,\;3.3\;\mu\textrm{g}/kg$, respectively, and showed 4.6% aflatoxin BI contamination in rice samples. Meanwhile, four out of 116 barley samples were positive. VB-37 showed the highest aflatoxin Bllevels of $9.6\;\mu\textrm{g}/kg$ and VB-35, VB-15 and VB-54 represent $7.5\;\mu\textrm{g}.kg,\;6.0\;\mu\textrm{g}/kg\;and\;3.6\;\mu\textrm{g}/kg$, respectively, and showed 3.4% aflatoxin B1 contamination in barley samples.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.204-208
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• 1992

This study was carried out to develop a practical enzyme-linked immunosorbent assay(ELISA) for the determination of soy protein in processed meat products as a preliminary study. The titer of antiserum raised in rabbit by injection of SDS-treated whole buffer extract(WBE) from isolates soy protein(ISP) was above 1:10,000 in indirect ELISA. When the SDS concentration was higher than 0.03% the antibody-antigen reaction was inhibited significantly. However, the antibody-antigen reaction inhibition was not observed when the SDS concentration was less than 0.02%. The antibodies used in this experiment also reacted with renatured antigen after removing SDS by dialysis, though not better than with SDS-denatured antigen(immunogen). The calibration curve with $100\;{\mu}g/100\;ml$ of sensitivity was obtained in indirect competitive ELISA.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.95-101
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• 1985

Fascioliasis in cattle is one of the most common and very serious trematode diseases in Korea. In the present study, the enzyme linked immunosorbent assay (ELISA) was applied in the diagnosis of fascioliasis using antigen of Fasciela hepatica, perokidase of conjugate anti-cattle Is G and orthophenylenediamine as a substrate by micro-method technique of Volley et at. (1976b) and MacLaren (1978) with a slight modification. Results obtained from the present study are as follows. 1. In assay for optimal dilution of stock antigen, the antigen (protein contents; 0. Bmgymz) was diluted from 1150 to 1/600 with carbonate buffer (pH 9.6), and then absorbance values were measured with 1/100 diluted sera. The regression equations between the OD values of ELISA and dilution of antigen were log Y: -0.181-0.00127X in infected sera, and log Y: -0.578-0. 000879X in normal sera. The significantly higher (p<0.05) OD value was observed in the former. 2. In assay for optimal dilution of sera, the sera were diluted from 1125 to 1/400 with in PBSJ Tween 20 (pH 7.4), and absorbance values were measured with 1/200 diluted antigen. The regression equation between the OD values of ELISA and dilution of sera were log Y: -0.1540-0.0007238X in infected sera and log Y: -0.4834-0.00116X in normal sera. The former was higher than the latter (p<0.05). 3. In the 27 cases of negative intradermal test, OD values of the ELISA are $0.447{\pm}0.144$, the 95% confidence interval (Mean+2 H SD) of the values was 0.735, and there was no case over the values. Therefore, the sensitivity of the antigen to diagnose fascioliasis was 100% in the negative case. The OD value 0.7 which is designed as a criterion (detection level of positive one) is useful for the performance of the ELISA in fascioliasis. 4. According to the OD value of criterion in the regression equations, the optimal dilutions of stock antigen and serum were 1/250 and 1/100, respectively. 5. In the 58 cases of fascioliasis from which the adult could be found in the bile ducts, the OD value was $0.846{\pm}0.224$. The 75% (44 cattle) among them had higher value with compared to the criterion, and the 60% (20 cattle) of the cases of proliferative cholangitis of 33 cattle which had been infected previousely with Fasciola sp. is higher than the criterion. 6. Prevalence of fascioliasis was 43.4% in the application of the ELISA to 272 cattle which were reared in Jeonbug district.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.149-154
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• 2007

In the present study, we performed the PCR assay using TOX2P/TOX2M primer targeting a specific region within mcyB gene to identify potential microcystin-producing cyanobacteria. TOX2P/TOX2M primer set was effective in amplifying mcy gene in the field samples containing Microcystis spp. of 1,000 cells per mL. Moreover, the results from the PCR assay agreed with those of the ELISA analysis. Consequently, this study demonstrated that TOX2P/TOX2M primer set can be used as a genetic probe for the early detection of cyanobacterial toxigenicity in Korean water bodies.