• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.633-642
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• 2002

Enteric colibacillosis has economically become an important disease of young animals as a result of increasing intensification of farrowing management. The objective of this experiment is to isolate fimbrial antigen from enterotoxigenic E. coli F41, to develop specific polyclonal IgY which can effectively neutralize or reduce the proliferation of pathogens in feed or living animal system, and to apply IgY technologies to animal industry. The results obtained were as follows: The molecular weight of the purified F41 antigen was 29,500 dalton on sodium dodecyl sulfate-polyacrylamide gels. Fimbrial antigen was confirmed by the western blot method. It was observed that after immunization the level of serum antibody titer of laying hen was shown in two weeks and gradually increased. The antibody titer in egg yolk appeared two weeks after it was shown in serum antibody. The titers of egg yolk antibody were gradually increased to the maximum level of 320,000 (antigen 50${\mu}g$/$m\ell$), 450,000 (antigen 200${\mu}g$/$m\ell$), and 320,000 (antigen 600${\mu}g$/$m\ell$). According to the results of specificity test by ELISA, the anti-F41 antibodies from chicken serum and egg yolk reacted only with ETEC F41 antigen. There was no cross reaction with other ETEC strains (K88, K99, and 987P). In vitro condition, as a result of antigen binding ability of yolk antibodies, bacterial concentration was rapidly decreased to $10^5$ CFU/$m\ell$ from $10^9$ CFU/$m\ell$ when 2${\sim}$4 mg/$m\ell$ of freeze dried WSF (water soluble fraction) was added.

• Archives of Pharmacal Research
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• v.15 no.4
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• pp.347-355
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• 1992

To elucidate structure of group "a" epitope, mouse antibodies that express idiotype monoclonal antibody and anti-idiotype monoclonal antibody against the group specific "a" determinant were purified by hydroxyapatite column. To obtain hepatitis B surface antigens (HBsAg). HBsAg positive blood was sequencially purified by ammonium sulfate precipitation, hydroxyapatite, sepharose 4B column chromatography and ultracentrifugation. The major protein (p25) and glycoprotein (gp30) of HBsAg were isolated by concanavalin-A-sepharose 4B. The ability of p25-gp30 among the HBsAg to inhibit the idiotype-anti-idiotype reaction was dependent on conformation, since reduced and alkylated p25-gp30 virtualy lost their inhibitory capacity when compared to native HBsAg. The data suggest that hepatitis B antigen is a conformational antigen critically dependent upon the disulfide bonds of p25-gp30.

• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.63-65
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• 1999

Although many pharmaceutically useful proteins are produced in E. coli expression system, it is very are rare for the system to be used in the production of diagnostic antigen due to a major problem, i.e., false-positive reaction of e. coli host-derived proteins contaminating purified diagnostic antigen with human sera. The N (nucleocapsid) protein of Seoul virus causing haemorrhagic fever with renal syndrome (HFRS) was produced in E. coli BL21 (DE3), and used for the detection of N protein-specific antibodies in human sera. Using the N protein as a diagnostic antigen of HFRS, the false-positive reaction was cleared by merely mixing the test sera with the extract of E. coli host strain not harboring expression plasmid.

• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.133-139
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• 1985

An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.

• Korean Journal of Veterinary Service
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• v.15 no.1
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• pp.32-45
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• 1992

In order to establish and enzyme-linked immunosorbent assay to ILTV, field virus strain of ILTV was propagated in chorioallantoic membrane of the embryonated eggs. purified and used as antigen. The antisera selected from the field samples and immunized chickens based on serum neutralization test were used as the standard positive and negative sera in all tests. It was found that optimal antigen concentration was $2{\mu}g$ of protein per well and a 1 : 100 dilution of standard serum showed low background optical density with negative serum and high P/N values of positive sera. A 1 : 500 dilution of the rabbit anti-chicken IgG peroxidase conjugate produced a high P/N values and thirty minutes was chosen as suitable time to read the optical density of the enzyme substrate reaction and optical density was consistent during the 16 hours after stopper was treated. When coated antigen was kept on microplate for varying time up to 16 hours at $4^{\circ}C$ or $37^{\circ}C,$ no significant difference was observed between the treatment. The coated antigen could be kept without change of antigenicity for at least one month at $-70^{\circ}C,\; -20^{\circ}C,\; 4^{\circ}C$ and room temperature. When blocking buffer contanining bovine serum albumin was mixed directly with conjugate and serum at 10% level induced higher P/N values compared to blocking antigen coated microplate with the same blocking buffer. The coefficience of correlation between ELISA and SN test was 0.577. When antibody response of chickens, vaccinated with ILTV, was examined by ELISA and SN test, antibody rising and decay pattern between the two test was similar until 11 weeks of age. However 12 weeks onward antibody titer checked on by SN test was slightly lower than that tested by ELISA.

• Journal of Aquaculture
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• v.10 no.4
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• pp.425-433
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• 1997

The isolated soluble eye proteins from six species (Sepia esculenta, Sepiella japonica, Loligo chinensis, Todarodes pacificus, Loligo beka and Ocotopus minor) of class Cephaloopoda were compared by crossed immunoelectrophoresis methods using antibodies directed against total soluble eye proteins antigens. It showed a distinct antigen-antibody reaction between the species of order Sepioidea and various antiserum of class Cephalopoda. Our results suggested that the common precipitation lines of Sepia and Loligo species which were different from that of Octopus minor. By which obtained from elution of gel filtration chromatography and 12.5% SDS-polyacrylamide gel electrophoresis, the molecular weight of Todarodes pacificus eye protein (crystallin) was determined in abut 20-35 KDa.

• Journal of Sensor Science and Technology
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• v.7 no.4
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• pp.263-270
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• 1998

Surface Plasmon Resonance (SPR) sensor system, has rapid response and high sensitivity, can be applicable for detecting reaction times of many biospecific interactions. A SPR sensor system was constructed to detect the antigen-antibody reactions of salmonella and hIgG (human immunoglobulin G). Sensor chips made of gold thin film were used for detecting biological bindings of antigen and antibody reactions. The antigen and antibody reactions for salmonella and hIgG were carried out with various time intervals to observed characteristics of these reactions using SPR sensor system. The resonance angle shift changes were clearly observed at the time of salmonella or hIgG antibody injection into sample cell since each antibody was self-assembled on gold chip surface of the sensor. It was found that the antibodies of salmonella and hIgG reacted with its sensor chip surface in 10 minutes and 60 minutes respectively. And the antigens of both salmonella and hIgG were bound to its antibody within 1 minute.

• Food Science of Animal Resources
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• v.18 no.2
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• pp.149-156
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• 1998

Chicken beef pork meats and isolated soy protein (ISP) were heated at 10$0^{\circ}C$ for 30min and then heat-resistant proteins were fractionated to examine cross-resistant protein from chicken meat but not with beef pork or ISP. Dot blotting using the polyclonal antibody showed that the sen-sitivity for detecting chicken meat was 1$\mu$m and antibody-antigen reaction was dose-dependant. Results of dot blotting analysis to compare the amount of chicken meat present in arket meat products(Kentucky Frank sausage;chicken meat 46.52% and pork 24.92% vs Bulgogi Ham;chicken meat 28.89% and turkey 31.44%)showed that the significant differences between two meat products in terms of chicken meat concentrations. Dose-dependant dot-blotting reaction was also observed in chicken meat samples with various dilution.

• Journal of the Korean Society of Visualization
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• v.13 no.1
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• pp.35-42
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• 2015

CD4+ T-cell count determines the effectiveness for antiretroviral therapy (ART) in patients with human immunodeficiency virus (HIV). Although ART slows the progression of HIV to AIDS, rapid counting of CD4+ T lymphocytes with a drop of patient's blood sample is urgently needed to ensure timely ART treatment in rural areas. Recently point-of-care CD4 testing devices have been developed by using non-flow based imaging cytometer incorporated with a sample cartridge where CD4+ T cells are reacted with fluorescently tagged specific antibodies. Here we conducted an experimental study using a conventional fluorescence microscope-based imaging system to quantitate the interaction of CD4 antibodies with CD4+ T cells at different reaction conditions. We demonstrated that a fast and affordable point-of-care CD4 test is feasible with a far less amount of antibodies and a shorter incubation time compared with a conventional sample preparation protocol for flow cytometry. We also proposed a general method to evaluate and compare the detection limit across different CD4 counting platforms by using fluorescently labelled microbeads for intensity calibration.

• Parasites, Hosts and Diseases
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• v.37 no.4
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• pp.243-248
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• 1999

The present study analyzed serum IgG subclass antibody reaction to major antigenic bands of Clonorchis sinensis to investigate improvement of its serodiagnosis. Of the four subclass antibodies, IgG1 and IgG2 antibodies were produced but not specific, IgG3 antibody was least produced, and IgG4 antibody was prominent and specific. The serum IgG antibody reaction to any of 43-50, 34-37, 26-28, and 8 kDa bands was found in 65.5％ of 168 egg positive cases while IgG4 antibody reaction was found in 22.0％ of them. The positive rates of IgG and IgG4 antibodies were directly correlated with the intensity of infection. All of the sera from heavily infected cases over EPG 5,000 showed positive reaction for specific IgG and IgG4 antibodies. The specific serum IgG4 antibody disappeared within 6 months after treatment. The bands of 35 kDa and 67 kDa cross-reacted with IgG antibodies but not with IgG4 antibodies in sera of other trematode infections. The present findings suggest that serum IgG4 antibody reaction to 8 kDa band is specific but not sensitive. Any method to increase its sensitivity is required for improved serodiagnosis.