• Archives of Pharmacal Research
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• v.10 no.1
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• pp.18-24
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• 1987

Mouse monocolonal antibodies to Hepatitis B surface antien (HBsAg) were prepared and their functional capabilities tested by the method of solid phase enzyme linked immuno sorbent assay (ELISA). HBsAg binding studies inicated that one monoclonal antibody 6E-1-1 bound more HBsAg at a faster rate than the other monoclonal antibodies. Also, for the binding inhibition studies with the selected monoclonal antibody 6E-1-1, one monoclonal antibody 8D-3-6 didn't exhibit binding inhibition for HBsAg. Then, a simultaneous ELISA method was developed for the immunodiagnosis of HBsAg. Different combinations of two monoclonal antibodies as solid phase and horseradish peroxidase (HRPO) labeled phase were studied. The combination of monoclonal antibody of higher affinity constant (6E-1-1) immobilized in a solid phase and monoclonal antibody of lower affinity constant (8D-3-6) as a HRPO laeled phase was more sensitive when two monoclonal antibodies of different affinity constants for HBsAg were prepared.

• Journal of Sensor Science and Technology
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• v.19 no.4
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• pp.306-312
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• 2010

We have detected deoxynivalenol(DON) using a metal-oxide-semiconductor field-effect-transistor(MOSFET)-based biosensor. The MOSFET-based biosensor is fabricated by a standard complementary metal-oxide-semiconductor(CMOS) process, and the biosensor's electrical characteristics were investigated. The output of the sensor was stabilized by employing a reference electrode that applies a fixed bias to the gate. Au which has a chemical affinity for thiol was used as the gate metal to immobilize a self-assembled monolayer(SAM) made of 16-mercaptohexadecanoic acid(MHDA). The SAM was used to immobilize anti-deoxynivalenol antibody. The carboxyl group of the SAM was bound to the anti- deoxynivalenol antibody. Anti-deoxynivalenol antibody and deoxynivalenol were bound by an antigen-antibody reaction. In this study, it is confirmed that the MOSFET-based biosensor can detect deoxynivalenol at concentrations as low as 0.1 ${\mu}g$/ml. The measurements were performed in phosphate buffered saline(PBS; pH 7.4) solution. To verify the interaction among the SAM, antibody, and antigen, surface plasmon resonance(SPR) measurements were performed.

• 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 Clinical Laboratory Science
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• v.47 no.4
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• pp.306-312
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• 2015

The measurement of histamine is to determine the degree of allergy because the allergic reaction can lead to the release of histamine. In general, the antigen-antibody reaction was quantified by measuring absorbance using a microplate reader. In this study, we compare the method using a general antigen-antibody reaction and the method using a high performance liquid chromatography mass spectrometer (HPLC-MS) of chemical analysis in the measurement of histamine secretion. The cell line used was RBL-2H3, an allergic reaction was induced by stimulation with C48/80 (compound 48/80). Allergy-induced cells degranulation rate was confirmed by measurement of ${\beta}$-hexosaminidase and cytotoxicity was performed for the validity of the experiment. The quantitative determination of histamine showed a significant difference, since the quantitative limit of the measurement by the antigen-antibody reaction was 10.257 ppm while the quantitative limit of the measurement by HPLC-MS was 0.020 ppm. Measurement of histamine in allergic activity and anti-allergy tests showed that the HPLC-MS analysis rather than the analysis of the antigen-antibody reaction is a more precise and accurate test.

• Parasites, Hosts and Diseases
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• v.55 no.6
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• pp.623-630
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• 2017

Plasmodium lactate dehydrogenase (pLDH) is a strong target antigen for the determination of infection with Plasmodium species specifically. However, a more effective antibody is needed because of the low sensitivity of the current antibody in many immunological diagnostic assays. In this study, recombinant Plasmodium vivax LDH (PvLDH) was experimentally constructed and expressed as a native antigen to develop an effective P. vivax-specific monoclonal antibody (mAb). Two mAbs (2CF5 and 1G10) were tested using ELISA and immunofluorescence assays (IFA), as both demonstrated reactivity against pLDH antigen. Of the 2 antibodies, 2CF5 was not able to detect P. falciparum, suggesting that it might possess P. vivax-specificity. The detection limit for a pair of 2 mAbs-linked sandwich ELISA was 31.3 ng/ml of the recombinant antigen. The P. vivax-specific performance of mAbs-linked ELISA was confirmed by in vitro-cultured P. falciparum and P. vivax-infected patient blood samples. In conclusion, the 2 new antibodies possessed the potential to detect P. vivax and will be useful in immunoassay.

• 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.

• Parasites, Hosts and Diseases
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• v.35 no.2
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• pp.87-94
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• 1997

Clonorchis sinearis is a liver fluke which is the most prevalent helminth of humans in Korea. The better diagnostic measure of clonorchiasis is required for its nationwide control program. The present study observed antigenic bands of C. sinensis and reacting immunoglobulins in serum of infected residents. Adult C. sinensis were recovered from experimentally infected rabbits and soluble crude extract of the worms was used as the antigen after supplementation of E-64, a cysteine proteinase inhibitor. SDS- PAGE of the crude antigen resolved more than 20 protein bands between 200 and 14 kDa. The sera of infected humans collected at an endemic village showed specific IgG and IgE antibodies but little IgM and IgA antibodies. The protein bands of 94, 80, 72, 68, 52, 47, 43, 37, 34, and 28-25 kDa strongly reacted with serum Ig(GMA) or IgG antibody and 64, 62, 52, 47,44, 34,28, and 26 kDa bands reacted with serum IgE antibody. However, the 94, 80, 72, 68, 64, 62, 52, 47, and 40 kDa bands of C. sinensis antigen were found non specific. The protein bands of 43, 34, and 28-25 kDa of C. sinensis are primary target molecules of further analysis.

• Parasites, Hosts and Diseases
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• v.46 no.3
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• pp.195-198
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• 2008

Plasmodium falciparum liver stage antigen-1 (PfLSA-1) is one of the few antigens expressed exclusively in liver stage parasites. In this study, we evaluated the antibody responses against recombinant PfLSA-1 in naturally infected individuals in Myanmar. High levels of antibody responses (70.7%) were detected in 82 serum samples from 116 infected individuals, and IgG responses to PfLSA-1 principally composed of responses of IgG1 and IgG3 subclasses. These results show that PfLSA-1 elicits effective antibody responses in individuals infected with P. falciparum, and thus it could be not only an attractive candidate protein for vaccine development, but also a useful antigen for serodiagnosis of the infection.

• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.51-58
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• 1972

Hemagglutinating antigen of Toxoplasma gondii was prepared and purified by the method of a slight modification of Tsunematsu, and the preparation of the skin test antigen (toxoplasmin) was made by means of acetone-ether treatment described by Nobute et al. With these antigens the passive hemagglutionation and skin tests were performed for the diagnosis of swine toxoplasmosis by using artificially infected pigs. The results obtained were summarized as follows: 1. The hemagglutinating antibody and the skin test antibody were demonstrated one and three weeks after infection, respectively. And these antibodies were maintained over nine weeks after infection. 2. The antigenicity of hemagglutinating antigen was stable when it was kept in frozen state, while was unstable in a liquid state. 3. Freeze-dried skin test antigen (toxoplasmin) was stable for two months or more if it was kept at $5^{\circ}C$ and room temperature, but in the liquid or reconstituted state it was unstable. 4. Freeze-dried skin test antigen could be preserved without loss of antigenicity for more than two months. 5. Passive hemagglutination test could be applied effectively at the early phase of the disease process and skin test at later phase, mainly for epidemiological survey. However, by combiniation of these methods, the more accurate results could be obtained.

• IMMUNE NETWORK
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• v.1 no.1
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• pp.1-6
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• 2001

The identification of tumor-specific antigens has represented a critical milestone in cancer diagnosis and therapy. Clinical research in this area for leukemia has also been driven over the past few decades by the hope that surface antigens with restricted tissue expression would be identified. Disappointingly, only a small number of the leukemic antigens identified to date, meet sufficient criteria to be considered viable immunophenotypic markers. In this paper, we nominate anti-JL1 monoclonal antibody as an immunodiagnostic and immunotherapeutic candidate for leukemia. The JL1 molecule appears to be a novel cell surface antigen, which is strictly confined to a subpopulation of limited stages during the hematopoietic differentiation process. Despite the restricted distribution of the JL1 antigen in normal tissues and cells, anti-JL1 monoclonal antibody specifically recognizes various types of leukemia, irrespective of immunophenotypes. On the basis of these findings, we propose JL1 antigen as a tumor-specific marker, which shows promise as a candidate molecule for diagnosis and immunotherapy in leukemia, and one that spares normal bone marrow stem cells.