• Agricultural and Biosystems Engineering
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• v.5 no.1
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• pp.21-24
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• 2004

Antibody based biosensors are very selective and ultra-sensitive. Antigen-antibody reactions have been used in immunoassays. In this research, a biosensor which uses antigen-antibody reaction was developed to measure and detect rat IgG. Because the antigen-antibody reaction is a physical bounding between antigen and antibody, there are several ways to measure an antigen-antibody reaction. Among the methods, impedance analysis has short measuring time and possibilities of analyzing various properties of the reaction using frequency analysis. Rat IgG could be detected with developed biosensor and impedance analyzer. The biosensor showed good repeatability and availability of detecting concentration changes of rat IgG.

• 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.

• The Journal of the Korean Society for Microbiology
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• v.22 no.4
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• pp.445-451
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• 1987

Coagglutination method is widely used for the diagnosis of Salmonella infection. This test, however, has a disadvantage of false positive reaction due to the coagglutination of staphylococci with non-specific immune complexes or anti-staphylococci antibody in serum. Salmonell O antigen was detected by enzyme immunoassay with protein A-bearing Staphylococcus aureus as in the solid phase. Horse radish peroxidase was labeled to IgG specific against Salmonella O antigen. This enzyme immunoassay was much more sensitive than conventional coagglutination method without false poitive agglutination. To improve the sensitivity for detection of Salmonella O antigen in samples, we tried to determine the optimal concentration of normal IgG that inhibits non-specific binding of horse radish peroxidase labeled IgG to staphylococci, and to establish the optimal condition of reaction between antigen-antibody complex and staphylococci. Non-specific binding of horse radish peroxidase labeled specific IgG to staphylococci was almost blocked when the enzyme labeled IgG was 500-fold diluted with phosphate buffered saline containing 2mg/ml of normal IgG. When staphylococci coated with antibody to Salmonella O antigen were mixed with antigen-antibody complex and then incubated for 1 hour at room temperature, the minimal detectable concentration of Salmonella O antigen was 1ng/ml. The sensitivity of enzyme immunoassay was 100-fold greater than a conventional coagglutination method. This enzyme immunoassay could be expected as an improved method for detection of other infectious agents.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.313-323
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• 1998

In order to establish a sensitive and specific diagnostic method for detection of antibody to Salmonella pullorum, a enzyme-linked immunosorbent assay(ELISA) was designed and standardized. The diagnostic efficacy of the established ELISA was compared with that of the serum plate agglutination test and immunodiffusion test for pullorum disease. 1. The chicken hyperimmune sera to Salmonella pullorum, S gallinarum, S typhimurium and S typhi were shown the cross reaction to S pullorum antigen by serum plate agglutination test. 2. When compared the cross reaction titer of microplate agglutination test for chickens hyperimmune sera, it was found that the titer were 64 in S pullorum, 32 in S gallinarum, 4 in S typhimurium and 8 in S typhi, respectively. 3. When compared the specificity of various antigen(HA, EA, PA and SA) by the immunodiffusion test, the most suitable antigen was phenol-treated bactrium. 4. The optimal concentration of S pullorum antigen for ELISA was 1 : 160 dilution of bacterium. 5. The efficacy of the ELISA for detection of S pullorum antibody was compared with serum Plate agglutination test and immunodiffusion test in chickens infected with S pullorum. The antibody was first detected at 6 days after infection using three tests examined. The antibody was alldetected at 9 days by ELISA, at 12 days by serumplate agglutination test, at 15 days by immunodiffusion test.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.43-49
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• 2001

As compared with reaction of antibody for sonicated antigen of Brucella abortus strain RB51 and 1119-3 by Western blot analysis, Brucella field positive sera was detected strong reaction at 40~80 kDa LPS of strain 1119-3, but detected very weak reaction at strain RB51 partly. Otherwise, as we analyzed major immunogen of RB51 by antisera bled periodically during 6 months after RB51 vaccination. we detected strong immunological reaction at 17, 18 and 8 kDa antigen of RB51. Especially, reaction of 8 kDa antigen by Western blot coincided with reaction of dot-blot assay in RB51-antibody detection method. We also compared with reaction of field sera by STAT(standard tube agglutination test), dot-blot assay and Western blot (reaction of 8 kDa antigen of strain RB51). 16 sera of 4~5 months after RB51 vaccination are all negative by STAT, and 12 field brucellosis positive serum are all positive, and also 12 of 16 sera vaccinated RB51 are positive by dot-blot assay and reaction of 8kDa antigen by Western blot. but 1 of 15 Brucellosis negative sera reacted nonspecifically dot-blot assay.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.515-516
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• 2012

• Parasites, Hosts and Diseases
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• v.47 no.2
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• pp.153-157
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• 2009

Diagnosis of hydatidosis is based on immunodiagnostic methods along with radiological and ultrasound examinations. The objectives of the present study were to develop a specific and simple antigen-based ELISA method for diagnosis of hydatidosis and compare it with antibody detection method. The subjects in this study included 89 patients in the following groups: surgically confirmed hydatidosis patients (35 cases), control with other parasitic diseases (29 cases), and healthy controls (25 cases). Hyperimmune serum was raised against hydatid cyst fluid in rabbits. Anti-hydatid cyst IgG was purified by affinity chromatography using protein A column and labeled with horseradish peroxidase. Collected sera were assessed for hydatid cyst antigens and antibody by ELISA. Circulating hydatid antigen was found in 9 out of 35 patients with surgically confirmed hydatidosis. A sensitivity of 25.7% and a specificity of 98.0% were calculated for the antigen detection assay. Antibody detection by indirect ELISA, using antigen B, showed that 94.2% of patients (33 cases) have anti-hydatid cyst antibodies in their serum while cross reaction was noted in a few of non-hydatidosis patients. A sensitivity of 94.2% and specificity of 81.6% were found for the antibody detection assay. Findings of this study indicated that antibody detection assay is a sensitive approach for diagnosis of hydatid cyst while antigen detection assay might be a useful approach for assessment of the efficacy of treatment especially after removal of the cyst.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.755-758
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• 2005

This paper describes the novel immunoassay sensing system for a portable clinical diagnosis system. It consists of a bead cage reactor and a CMOS integrated biosensor. It showed the simple and easy antibody coating method on beads by flow-through avidin biotin complex technology in a microfluidic device. It showed just 90 nL sample consumption and good result for the application of alpha feto protein. The bead cage reactor has the role of the antibody coating, antigen binding and enzyme linking for the electrochemical sensing method. The CMOS biosensor consists of ISFET (ion selective field effect transistor) biosensor and temperature sensor for detecting pH that is the byproduct of enzyme reaction. The sensitivity is 8 $kHz/^{\circ}C$ in a temperature sensor and 33 mV/pH in a pH sensor. After filling the 15 um polystyrene beads in bead cage, antibody flowed and reacted to beads. Subsequently, the biotinylated antigen flowed and bound to the antibody and GOD (glucose oxidase)-avidin conjugate flowed and reacted to the biotin of the biotinylated antigen. After this reaction process, glucose solution flowed and reacted to the GOD on beads. The hydrogen was generated by glucose-GOD reaction. And it was detected by the pH sensor.

• 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.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.7-12
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• 1987

The indirect fluorescent antibody(IFA) test was used to detect serum IgG and IgM antibodies to Trichomonas vaginalis in 31 vaginal trichomoniasis, 7 candidiasis and in 20 non-infected healthy women with antigen prepared from axonic culture of Trichomenas vaginalis isolated from vulvovaginitis patient. The results were as follows: 1. In 31 vaginal trichomoniasis the positive reactions of IgG antibody were 27 in the 1/8 dilution or higher and :l in the 1/4 dilution whereas in healthy women the reaction showed significantly low as in the 1/4 dilution or below. 2. The sensitivity and specificity of IFA test for IgG antibody to trichomonad antigen in this study were 87.1% and 100%, respectively. 3. No significant difference of IgM antibody levels between vaginal trichomoniasis and healthy women was observed. 4. No relation between the levels of IgG and IsM antibodies to trichomonad antigen by IFA test was observed. 5. No relation between the time lapse and the level of serum IgG antibodies in IFA test of vaginal trichomoniasis was regarded. In conclusion the present study suggests that IFA test in trichomoniasis could be a useful tool for detection of anti-trichomonad IgG antibodies and applicable as an immunodiagnostic method.