• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.72-77
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• 1999

An antibody containing a genetically engineered lipid group at the N-termunus and a hexahistidinyl tag at the C-terminus (Lpp-scF-His6) was immobilized in an oriented manner on the surface of liposome. Liposomes, consisting of antibody and phosphatidyl-choline, have been prepared and imaged by AFM. For AFM visualization, the resulting liposomes were bound on the surface of mica by two different mechanisms. The histidine tags present in the antibody molecules of the immonuliposome were anchored to the NiCl2 treated mica surface. Alternatively, the immunoliposomes were immunochemically bound on antigen-coated mica surface. Both approaches yielded liposomes which were clearly imaged without damage by AFM in ambient condition.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.15-19
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• 2008

This research was conducted to develop a quick and sensitive method of detecting carbamate residues using the immobilization of antibody-antigen interactions with surface plasmon resonance (SPR). We have used commercialized surface plasmon resonance equipment (Biacore 3000). The antibody used for the immunoassay was specific for glutathione-s-transferase (GST) and the antigens included several carbamate pesticides (carbofuran, carbaryl, and benfuracarb). When antigens were applied to the protein GST, the detection limit was 2 ng/mL of carbamate pesticide. The fabricated protein GST maintained its activity for over 200 measurements. Thus we determined that the SPR biosensors could detect the specific reversible binding of a reactant in solution to a binding partner immobilized on the surface of the sensor and allow real-time detection and monitoring.

• Journal of Powder Materials
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• v.16 no.3
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• pp.180-184
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• 2009

In this paper, the electrochemical non-enzyme immunosensor has been developed for the determination of salmonella antigen, using inverse voltammetry. For the estimation of salmonella antigen concentration, the $Fe_3O_4$ nanoparticles synthesized by microemulsion method were conjugated with salmonella antigen. Then, the immunocomplex between antibody immobilized on the transducer surface and antigen containing a magnetic nanoparticles was formed. From the linear relationship between the reduction peak current of Fe(III) and salmonella antigen concentration, it is suggested that the electrochemical non-enzyme biosensor is applicable to detect salmonella antigen in the concentration range of $10^1-10^5$ CFU/ml.

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.37-42
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• 1993

Surface proteins of Trichomonqs unginnlis (T vqsinalis) were analyzed to study the antigenic variation. The surface proteins of protozoa were labelled by N- hydrokysuccinimide-biotin (NHS-biotins, the NHS-biotin-labelled proteins were immunoprecipitated with rabbit antiserum to purifjr the antigenic fractions and analysed by SDS-PAGE plus electroblotting. The results obtained in this study were as follows; Biotinylated T. uaginalis-proteins obtained from intact cell and cells disrupted prior to labelling were detected by antibiotin-peroxidase in Western blots. Labelled proteins were immunoprecipitated by T. vcqinalis-immunized rabbit serum and the six bands with, the molecular weights of 46, 60, 68, 90, 130 and 220 kDa were identified as having antigenicity. T unginalis HY-1,HY-15 and ATCC 50148 were immunoprecipitated by immune rabbit serum after biotinylation and there were no difference from antigenic bands among these strains by this tehchnique. In conclusion with the results obtained in the present study, it was assumed that surface proteins of T vaqinclis were labelled by biotinylation and the six labelled bands at 46, 60, 68, 90, 130 and 220 kDa in their molecular weight were identified as having antigenicity by immunoprecipitation (IPI and this biotinylation-IP technique may be used for further study of surface antigen of T vaginalis.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.222-227
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• 2018

Mycobacterium tuberculosis (MTB)-originated lipid antigen is presented on the antigen-presenting cell surface with CD1b. When monocyte-derived dendritic cells phagocytosed MTB H37Rv (Multiplicity of infection 10, infectivity: 46.89%), the CD1b expression level decreased slowly. Since this was just a live MTB-mediated phenomenon, it was not detected from heat-killed MTB or mycolic acid, which is a unique antigen of MTB. We confirmed that the phosphorylation of CD1b molecules using 2D electrophoresis with staining could phosphorylate and induce the presentation of the lipid antigen using the phagocytosis assay.

• KSBB Journal
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• v.17 no.1
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• pp.20-25
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• 2002

We performed a basic experiment for rapid, on-line, real-time measurement of HBsAg by using a surface plasmon resonance biosensor to quantify the recognition and interaction of biomolecules. We immobilized the anti-HBsAg polyclonal antibody to the dextran layer on a CM5 chip surface which was pre-activated by N-hydroxysuccinimide for amine coupling. The binding of the HBsAg to the immobilized antibody was measured by the mass increase detected by the change in the SPR signal. The binding characteristics between HBsAg and its antibody followed typical monolayer adsorption isotherm. When the entire immobilized antibody was interacted, there was no additional, non-specific binding observed, which suggested the biointeraction was very specific as expected and independent of the ligand density. No significant steric hindrance was observed at 17.6 nm/$mm^2$ immobilization density. The relationship between the HBsAg concentration in the sample solution and the antigen bound to the chip surface was linear up to ca. $40\mu\textrm{g}$/mL, which is much wider than that of the ELISA method. It appeared the antigen-antibody binding was increased as the immobilized ligand density increased, but verification is warranted. This study showed the potential of this biosensor-based method as a rapid, simple, multi-sample, on-line assay. Once properly validated, it can serve as a more powerful method for HBsAg quantification replacing the current ELISA method.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.206-216
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• 2015

To clarify the role of surface protective antigen A (SpaA) in the pathogenesis of Erysipelothrix rhusiopathiae C43065 (serotype 2), the spaA deletion mutant of E. rhusiopathiae ${\Delta}spaA$ was constructed by homologous recombination. The virulence of the ${\Delta}spaA$ mutant decreased more than 76-fold compared with that of the wild-type strain C43065 in mice. The mutant strain was sensitive to the bactericidal action of swine serum, whereas the wild-type strain was resistant. The adhesion of wild-type strain to MEF cells was inhibited significantly by treatment with rabbit antiserum against recombinant SpaA (rSpaA) as compared with the treatment with normal rabbit serum, but the mutant strain was not affected. The mutant strain was readily taken up by mouse peritoneal macrophages in the normal rabbit serum, whereas the wild-type strain was resistant. Whereas the rabbit antiserum against rSpaA promoted the phagocytosis of wild-type strain by macrophages, the mutant strain was not affected. In addition, mice vaccinated with the formalin-killed mutant strain were provided 40% protection against challenge by the homologous virulent strain as compared with those with wild-type strain, NaOH-extracted antigen, or rSpaA, which provided more than 80% protection against the same infection. These suggested that SpaA has an important role in the pathogenesis of E. rhusiopathiae infection and could be a target for vaccination against swine erysipelas.

• The Journal of Korean Society of Virology
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• v.27 no.2
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• pp.129-135
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• 1997

Serum samples from 123 males and 123 females collected by age in 1996 were analyzed for antibodies against surface antigen of Hepatitis B virus and C22-3, C200 antigens of Hepatitis C virus. Sera from the children under the age of 10 showed 30% seropositivity to the surface antigen of Hepatitis B virus, 33.3% in $10{\sim}19$ year group, 20% in $20{\sim}29$ year group, 17.6% in $30{\sim}39$ year group, 3.3% in $40{\sim}49$ year group, 5.9% in $50{\sim}59$ year group, 8,3% in $60{\sim}69$ year group, 2.9% in $70{\sim}79$ year group, but antibody could not found in $80{\sim}86$ year group. 12 out of 123 male sera were positive, 19 out of 123 female sera were positive and overall rate of positivity of antibody against surface antigen of Hepatitis B virus was 12.6%. Serum samples from peoples under the age of 30 had not antibody against C22-3, C200 antigens of Hepatitis C virus. The positivity rate was 2.9% in $30{\sim}39$ year group. 5 out of 30 sera from $40{\sim}49$ year age group were positive, and 3 positive sera showed extremely high titer (1:524,288) but the titers of two remaining sera were 1:32, 1:8,192 respectively. 5.9% was positive in $50{\sim}59$ year group, 8.3% in $60{\sim}69$ year group, 11.8% in $70{\sim}79$ year group but all negative in $80{\sim}86$ year group 6 out of 123 male sera were positive (4.9%), 9 out of 123 female sera were positive (7.3%). Overall rate of positivity of antibody against C22-3, C200 antigen of Hepatitis C virus was 6.1 %. None out of 246 sera had both antibodies against Hepatitis B virus and Hepatitis C virus.

• Laboratory Medicine and Quality Assurance
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• v.40 no.2
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• pp.51-69
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• 2018

As part of the immunoserology program of the Korean Association of External Quality Assessment Service, we organized two trials on the external quality assessment of hepatitis viral markers in 2016 and 2017. The hepatitis viral antigens and antibodies program consisted of 10 test items. We delivered two and three types of pooled sera specimens to 965 and 965 institutions for the first and second trials of external proficiency testing in 2016, respectively. The number of participating laboratories was 915 (94.8%) and 913 (95.0%) in the first and second trials in 2016, respectively. We also delivered three kinds of pooled sera specimens to 936 and 1,015 institutions for the first and second trials of external proficiency testing in 2017, respectively. The number of participating laboratories was 920 (98.3%) and 996 (98.1%) in the first and second trials in 2017, respectively. The most commonly tested items were hepatitis B surface antigen, followed by the antibodies to hepatitis B surface antigen, anti-hepatitis C virus, hepatitis B envelope antigen, antibodies to hepatitis B envelope antigen, anti-hepatitis A virus and antibodies to hepatitis B core antigen. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay and the electrochemiluminescence immunoassay, but they yielded a few-false positive results due to the matrix effect. The immunochromatographic assay yielded false-negative results for anti-hepatitis A virus due to low sensitivity. Continuous improvement in the quality of viral hepatitis testing through participation in the survey seems necessary.

• Journal of Sensor Science and Technology
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• v.25 no.4
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• pp.243-246
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• 2016

The characteristics of a bimetallic surface plasmon resonance (SPR) chip were investigated to detect a tumor biomarker, carcinoembryonic antigen (CEA). The linewidth and the tangential slope of the reflectance curve of the bimetallic SPR chip was compared with those of the reflectance curve of a conventional gold (Au) SPR chip. The changes in reflectance in response to the variation in CEA in the critical concentration range were analyzed at an angle where the tangential slope of the reflectance curve was maximum. From linear regression analysis, the sensitivity of the bimetallic SPR chip with respect to the CEA in critical concentration was obtained.