• 한국연초학회지
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• 제12권1호
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• pp.29-38
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• 1990

Until relatively recently plant scientists have made little use of immunological techniques. Now, however, more and more researchers are discovering the powder of these techniques for the screening of immunomodulators and for the detection, quantitative determination and localization of compounds in plant materials. Especially, the recent developments in the fields of plant biotechnology and plant genetic engineering make it even more important for forkers in the plant sciences to become acquainted with the more sophisticated methods. The possible methods include onestep purification of antigens, visualization in situ by immunocytochemis try and on polyacrylam ids gel s by ni trocellulose Western blotting and quantification by various immunoassay. Among them, in this reviews, the quantitative determination methods are to be reviewed. There are several kinds of methods for the quantitative determination of plant constituents such as colorimetry, TLC, GLC, DCC, UV derivatization, densitometry and HPLC. When the complexity of plant constituents is considered. densitometry and HPLC have many advantages in sensitivity and separation ability. After a 11 some advarltages of two methods meritiorled above, all of these methods have many disadvantages and inconveniences. Previous purification for the application of all these methods make them less sensitive and more tedious. Immunoassay can solve these problems in part. But immunoassay also has some limitations. Specificity of immunoassay, contrary, can be considered to be disadvantages. Including this the advantages and disadvantages of immunoassay are to be discussed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제7권2호
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• pp.153-162
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• 2004

목적: H. pylori 대변항원(Helicobacter pylori stool antigen; HpSA) 검사는 H. pylori 감염 여부를 진단하는 데 이용되는 비침습적 검사이지만, 소아에서 제균요법 후 H. pylori 대변항원검사의 유용성에 대한 연구가 거의 이루어지지 못한 상태이다. 본 연구에서는 소아에서 H. pylori의 제균 여부를 확인하는 데 있어 enzyme immunoassay에 의한 HpSA 검사의 진단 정확도를 평가하고자 하였다. 연구방법: 2001년 1월부터 2003년 10월까지 서울대학교병원 소아과에서 146명의 소아(평균 연령 $9.3{\pm}4.3$세)를 대상으로 총 164회의 H. pylori 대변항원검사(Primier platinum HpSA)를 시행하였다. H. pylori 감염여부를 확인하기 위해 모든 환아에서 H. pylori 대변항원검사와 상부위장관내시경에 의한 위점막 생검을 병행하였다. H. pylori 감염이 확인되어 사제요법(omeprazole, amoxicillin, metronidazole, bismuth subcitrate)을 1주 동안 시행 받은 환아들에서는 치료 종결 후 최소 4주가 경과하였을 때 위내시경과 H. pylori 대변항원검사를 반복 실시하였다. H. pylori 대변항원검사는 OD값이 0.16 이상일 때 양성, 0.14~0.16 사이는 감염 미확정, 0.14 미만은 음성으로 판정하였다. 결과: 1) 제균 전 시행한 131회의 위내시경 조직검사 결과 28명이 H. pylori 양성이었고 나머지 103명은 H. pylori 음성이었다. 동시에 시행한 H. pylori 대변항원검사 결과에서 30명이 H. pylori 양성이었고, 101명이 음성으로 판정되었다. 따라서 제균요법 시행 전 H. pylori 대변항원검사의 민감도, 특이도, 양성 예측치, 음성 예측치는 각각 96.4%, 97.1%, 90% 그리고 99%이었다. 2) 제균요법 4주 후 33명의 환아에서 시행한 위내시경에 의한 조직검사에서 H. pylori는 24명에서 음성이었으나 9명은 여전히 양성이었다. 동시에 시행한 H. pylori 대변항원검사는 10명에서 양성, 23명에서 음성이었다. 따라서 제균요법 후 H. pylori 대변항원검사의 민감도, 특이도, 양성 예측치, 음성 예측치는 각각 88.9%, 91.7%, 80% 그리고 95.7%이었다. 결론: 소아에서 H. pylori 대변항원검사는 제균 후에도 높은 진단 정확도를 보였다. 따라서 H. pylori 대변항원검사는 소아에서 제균요법 후 균 박멸여부를 확인하는 데에도 매우 유용한 비침습적인 검사방법이라고 하겠다.

• 센서학회지
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• 제15권3호
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• pp.158-163
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• 2006

This paper reports a novel immunoassay method using superparamagnetic nanoparticles and an enhanced magnetic field gradient for the detection of protein in a microfluidic device. We use superparamagnetic nanoparticles as a label and fluorescent polystyrene beads as a solid support. Based on this platform, magnetic force-based microfluidic immunoassay is successfully applied to analyze the concentration of IgG as model analytes. In addition, we present ferromagnetic microstructure connected with a permanent magnet to increase magnetic flux density gradient (dB/dx, ${\sim}10^{4}$ T/m), which makes limit of detection reduced. The detection limit is reduced to about 1 pg/mL.

• 대한수의학회지
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• 제29권1호
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• pp.21-25
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• 1989

This experiment was carried out to determine the progesterone concentration of bovine plasma by liquid phase double antibody enzyme immunoassay. The optimum conditions of assay-system, enzyme conjugate and gelatin were invested. The sensitivity, recovery rate and reproducibility by this assay were also analyzed. The results obtained were as follows: 1. The suitable supplementation level of gelatin was 0.2%. As the gelatin level increased to 1%, coefficient variation of interassay was shown to be irregular. 2. The optimum dilution rate of enzyme conjugate was 30 times. Enzyme activity was greatly fluctuated depending on the minor condition of enzyme conjugate technique. Therefore, it was considered to be checked when determined. 3. The sensitivity of the assay was 12 pg/tube. 4. Recovery rate was decreased when the amount of sample was too little or too much, but the recovery rate was high as 97.8% when the amount of sample between 50 and $200{\mu}l$. 5. Mean intra-assay and inter-assay coefficient of variation was 4.5% and 5.9%, respectively. By using liquid phase double antibody enzyme immunoassay, progesterone in plasma can be detected, and also this assay system is applicable to study on physiological function of progesterone and to diagnosis of reproductive disorders.

• 대한미생물학회지
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• 제22권4호
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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.

• IMMUNE NETWORK
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• 제6권1호
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• pp.43-51
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• 2006

Background: The DR-$70^{TM}$ immunoassay is a newly developed cancer diagnostic test which quantifies the serum fibrin degradation products (FDP), produced during fibrinolysis, by antibody reaction. The purpose of this study was to evaluate the potential of DR-$70^{TM}$ Immunoassay in screening malignant tumor. Methods: Sample subjects were 4,169 adults, both male and female, who visited the health promotion center of a general hospital from March 2004 to April 2005 and underwent the DR-$70^{TM}$ immunoassay test and other tests for cancer diagnosis. The patient group was defined as 42 adults out of the sample subjects who were newly diagnosed with cancer during the same time period when the DR-$70^{TM}$ immunoassay test was performed. Final confirmation of a malignant tumor was made by pathological analysis. Results: The mean DR-$70^{TM}$ level was $0.83{\pm}0.65{\mu}g/ml$ (range: 0.00 (0.0001)${\sim}7.42{\mu}g/ml)$ in the control group (n=4,127) as opposed to $2.70{\pm}2.33{\mu}g/ml$ (range: $0.12{\sim}9.30{\mu}g/ml)$ in the cancer group (n=42), and statistical significance was established (p<0.0001, Student t-test). When categorized by the type of malignant tumor, all cancer patients with the exception of the subgroups of colon and rectal cancer showed significantly higher mean DR-$70^{TM}$ levels compared with the control group (p<0.0001, Kruscal-Wallis test). The receiver operating characteristic (ROC) curve analysis revealed ${\geq}1.091{\mu}g/ml$ as the best cut-off value. Using this cut-off value, the DR-$70^{TM}$ immunoassay produced a sensitivity of 71.4%, a specificity of 70.1%, a positive predictability of 69.4%, and a negative predictability of 69.2% (1). Conclusion: A significant increase in the mean DR-$70^{TM}$ value was observed in the cancer group (thyroidal, gastric, breast, hepatic and ovarian) com pared with the control group. In particular, the specificity and sensitivity of the DR-$70^{TM}$ immunoassay was relatively high in the subgroups of breast, gastric, and thyroidal cancer patients. There is need for further studies on a large number of malignant tumor patients to see how the DR-$70^{TM}$ level might be changed according to the differentiation grade and postoperative prognosis of the malignant tumor.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3191-3192
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• 2013

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1485-1490
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• 2012

An electrochemical immunoassay based on osmium-hippuric acid (HA) conjugate films onto the electrode is presented for the detection of urinary HA. This is the first report on the use of the oxidative electropolymerization of 5-amino-1,10-phenanthroline (5-$NH_2$-phen) for immobilizing an antigen, osmium-conjugated HA. As a redox mediator, [Os(5-amino-1,10-phenanthroline)$_2$(4-aminomethylpyridine-HA)Cl]$^{+/2+}$ (Os-phen-HA) was successfully synthesized and electropolymerized onto the screen-printed carbon electrodes (SPCEs). The interaction between osmium-HA conjugate films and antibody-HA ($anti$-HA) was performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electrical signals were linearly proportional to urinary HA in the range of 0.1-5.0 mg/mL, which is sufficient for use as an immunosensor using a cutoff concentration of 2.0 mg/mL in urine samples. The proposed electrochemical immunoassay method can be extended to various applications for detecting a wide range of different small antigens in the health care area.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.19-19
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• 2005

This paper reports a novel magnetic force-based microfluidic immunoassay using microbeads and magnetic nanoparticles. The magnetic force-based immunoassay was devised first and successfully applied to detect the rabbit IgG as the model analyte of microfluidic sandwich immunoassay. The microchannels were fabricated by poly(dimethysiloxane) (PDMS) molding processes and bonded on a slide glass by plasma treatment. At the part of the inlet, sample solution was hydrodynamically focused. The focused microbeads of sample solution were flowed through the 150 ${\mu}m$ width channel of outlet. However, when the microbeads are conjugated with the superparamagnetic nanoparticles under the applied magnetic fields, they will switch their flow path and flow through the 95 ${\mu}m$ width channel of outlet. The movements of microbeads conjugated with magnetic nanoparticles were demonstrated by magnetic field $gradients.^{1)}$ High magnetic field gradients using micro electromagnets could be applied to this detection method for high sensitivity and lower detection limit. In addition, the multiplexed $immunoassay^{2)}$ using an encoded microbead which is immobilized with a certain antibody could be possible using this detection principle.

• 대한기계학회논문집A
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• 제28권9호
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• pp.1429-1434
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• 2004

Immunoassay is one of the important analytical methods for clinical diagnoses and biochemical studies, but needs a long time, troublesome procedures and expensive reagents. In this study, therefore, we propose the micro filter chip with microbeads for immunoassay, which has pillar structures. The advantage of the proposed micro filter chip is to use simple fabrication process and cheap materials. The mold was made by the photolithography technique with Si wafer and negative photoresist SU-8. The replica was made of PDMS, bonded on the pyrex glass. The micro filter chip consists of inlet channel, filter chamber and outlet channel. HBV (Hepatitius B virus) monoclonal antibody (Ag1) labeled with biotin were immobilized onto streptavidin coated beads of 30∼50 $\mu$m size. Fluorescein isothiocyanate (FITC)-labeled HBV monoclonal antibody (Ag8) was used to detect HBsAg (Hebatitis B virus surface Antigen), and fluorescence intensity was monitored by epi-fluorescence microscope. In this study, the immune response of less than 30 min was obtained with with the use of 100 $m\ell$ of sample.