• 대한수의학회지
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• 제28권2호
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• pp.321-325
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• 1988

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, double (first and second) antibody and carrier (normal rabbit serum) were investigated. The optimum dilution rate of first antibody, second antibody and normal rabbit serum was $10{\times}10^3$ to $15{\times}10^3$, 20 and $1{\times}10^3$ times, respectively.

• 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.

• 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.

• 한국미생물·생명공학회지
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• 제17권4호
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• pp.365-369
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• 1989

Tyichoderma viride가 생산하는 cellobiohydrolase의 열불활화 특성을 잔류효소역가 측정방법과 면역학적 정량방법으로 측정하였다. 정제된 cellobiohydrolase의 열불활 곡선은 Arrhenius plots에서 직선관계를 가졌고 이 때의 Z-값은 carboxymethyl cellulase의 정량시 5.2$^{\circ}C$, filter pa per degradation activity 정량시 6.4$^{\circ}C$, Immunoassay시 5.8$^{\circ}C$로 각기 나타났다. 열역학 상수 산출시는 immunoassay 와 filter paper degradation activity 측정이 carboxymethyl cellulase의 역가 측정보다 잘 일치하는 것을 알 수 있었다.

• 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.

• BMB Reports
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• 제34권1호
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• pp.47-50
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• 2001

A one-step, two-site enzyme immunoassay was developed for measuring human alpha-fetoprotein (AFP) in serum and amniotic fluid using monoclonal antibodies (McAb) by eliminating the high-dose hook effect. Three McAbs that recognize different epitopes were selected among 16 different clones on the basis of epitope mapping, two for immobilization and one for horseradish peroxidase conjugation. This one-step immunoassay system is more convenient and rapid compared to a conventional two-step sandwich immunoassay system. It did not exhibit the hook effect to around 2.7 mg/ml of AFP, which is probably one of the highest concentrations of AFP in the serum. The dose-response curve of the system was linear to 500 mg/ml of AFP and the system could differentiate as low as 1 mg/ml of AFP The intra- and inter-assay variations were in an acceptable range; 95~104% and 97~105% respectively Its correlation with other commercial systems was around 95%.

• Molecules and Cells
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• 제21권2호
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• pp.308-313
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• 2006

Amygdalin is a cyanogenic glycoside compound which is commonly found in the pits of many fruits and raw nuts. Although amygdalin itself is not toxic, it can release cyanide (CN) after hydrolysis when the pits and nuts are crushed, moistened and incubated, possibly within the gastrointestinal tract. CN reversibly inhibits cellular oxidizing enzymes and cyanide poisoning generates a range of clinical symptoms. As some pits and nuts may contain unusually high levels of amygdalin such that there is a sufficient amount to induce critical CN poisoning in humans, the detection of abnormal content of amygdalin in those pits and nuts can be a life-saving measure. Although there are various methods to detect amygdalin in food extracts, an enzyme immunoassay has not been developed for this purpose. In this study we immunized New Zealand White rabbits with an amygdalin-KLH (keyhole limpet hemocyanin) conjugate and succeeded in raising anti-sera reactive to amygdalin, proving that amygdalin can behave as a hapten in rabbits. Using this polyclonal antibody, we developed a competition enzyme immunoassay for determination of amygdalin concentration in aqueous solutions. This technique was able to effectively detect abnormally high amygdalin content in various seeds and nuts. In conclusion, we proved that enzyme immunoassay can be used to determine the amount of amygdalin in food extracts, which will allow automated analysis with high throughput.

• 대한수의학회지
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• 제32권3호
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• pp.429-434
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• 1992

This study was carried out to develop an effective liquid-phase double antibody enzyme immunoassay for determining of progesterone. The optimum conditions of assay system, 1st and 2nd antibodies, enzyme conjugate, and time reaction were invested. The bovine plasma progesterone level in dairy cattle and korean native bulls were also analyzed. The results obtained were as follows; 1. The reproducibility of petroleum ether was superior to that of ethyl ether as extract solvent of progesterone in plasma. 2. The optimum dilution rate of 1st and 2nd antibody was 30,000 and 10 times, respectively. Affer the reaction of enzyme conjugate to progesterone 1st antibody, and then 2nd antibody competition reaction was enough for over 1hr. 3. Average plasma progesterone level in 4 pregnant and 9 nonpregnant Holstein was $2.5{\pm}0.5$ and $0.7{\pm}0.2ng/m{\ell}$, respectively. Average plasma progesterone level of 10 Korean native bulls was $0.1{\pm}0.001ng/m{\ell}$ From these results, by using liquid phase double antibody enzyme immunoassay for progesterone is applicable to detect of early pregnancy diagnosis, factorial analysis of reproductive disorder, and also reproductive physiological function such as monitoring of cyclicity during the post-partum period.

• 한국식품과학회지
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• 제32권2호
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• pp.439-443
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• 2000

시설원예산물 중 DON 생성능이 있는 균주의 오염 여부를 조사하기 위해 진주를 비롯한 서부 경남 일원과 경북 안동 근교에서 총 192점의 시료를 분리하여 균 분리를 실시한 결과 Fusarium속 103균주를 분리하였다. 분리된 균을 YES배지로 $28^{\circ}C$, 15일 배양한 후 ethyl acetate로 추출하여 thin layer chromatography(TLC)법으로 확인한 결과 DON 생성 균주 8개가 확인되었다. Enzyme amplification system immunoassay법을 이용하여 DON 생성 균주 8개를 정량한 결과 검출범위는 $0.007-1.21\;{\mu}g/mL$ 이었다. 이 중 남해 토양에서 분리한 32-D-3 균주가 $1.21\;{\mu}g/mL$로 가장 높았다.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1002-1009
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• 2007

A rapid, convenient homogeneous competitive enzyme immunoassay for estimating the amount of fenthion is described. The assay utilizes glucose-6-phosphate dehydrogenase-hapten conjugates that are inhibited in solution by antibodies obtained from bovine serum albumin-hapten conjugates. In order to investigate the effects of bridging group recognition on the sensitivity of dose response characteristics, the bridging groups of varying alkyl chain length were attached at the phosphate position of fenthion. Among the antibodies used, the one obtained from the use of hapten (fenthion analog) with the same bridging group structure that was used in preparing the enzyme-fenthion conjugates showed maximum inhibition (up to 51.8%) in the absence of fenthion. In the presence of fenthion, the activity of the enzyme-hapten conjugate is regained in an amount proportional to the fenthion concentration. Under the optimized condition, the $ED_{50}$ value for fenthion was $0.809{\mu}g/ml$. The assay developed in this study is a rapid effective screening method for fenthion prior to precise analysis.