• BMB Reports
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• 제33권4호
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• pp.353-357
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• 2000

A new assay method of ${\alpha}-Oxidase$ (fatty acid : oxygen dioxygenase, 1-decarboxylating) was developed using a bioluminescence reaction system of marine luminous bacterium, Photobacterium phosphoreum. ${\alpha}$-Oxidase was isolated from a cucumber (Cucumis sativus). Pentadecanoic acid was used as a substrate, and the product, tetradecanal, was analyzed with a bacterial luciferase-coupled reaction. Initial light intensity was directly related to the concentration of tetradecanal in the range of 1 nM to 10 ${\mu}M$. Optimal pH and temperature were 7.5 and $25^{\circ}C$, respectively. Optimal pentadecanoic acid concentration in a standard assay of ${\alpha}$-oxidase was 0.1 mM. The Km value of pentedecanoic acid was $85{\mu}M$. This method is straightforward, rapid, convenient, and easy. Its needs no treatment or extraction of reaction mixture.

• BMB Reports
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• 제36권4호
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• pp.417-420
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• 2003

The present work describes a colorimetric microplate assay for lipase activity based on the reaction between 5,5'-dithiobis(2-nitro benzoic acid) (DTNB) and the hydrolysis product of 2,3-dimercapto-1-propanol tributyrate (DMPTB). Reaction mixtures containing DTNB, DMPTB, and lipase were prepared in microplate wells, and the absorbance at 405nm was recorded after incubation at $37^{\circ}C$ for 30 min. A linear relationship was obtained in the range of 0.1-1 U of lipase activity by this method. The reaction conditions were also optimized for the range of 0.01-0.1 U or 1-10 U. When assaying crude tissue extracts, the reaction of DTNB with non-specific reducing agents created a major source of error. However, this error was corrected by the use of blank samples that did not contain DMPTB.

• Applied Biological Chemistry
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• 제25권3호
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• pp.182-188
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• 1982

일차아민과 반응하여 형광활성화합물을 형성하는 fluorescamine을 이용하여 어떤 시료중에 포함된 극미량의 trypsin inhibitor의 함량 또는 그 활성도를 측정하는 형광방법을 기술하였다. 세 가지 두류종실 즉 대두, 녹두 및 팥의 상대적 antitryptic activity 측정을 예로들어 본방법의 분석화학 우적수성을 여러 각도에서 검토하였던바, 효소반응속도론적 접근으로 이루어진 본방법은 동일한 접근으로 이루어진 기존의 흡광광도방법과 비교하여 측정감도는 대략 100배이상이였으며 casein과 같은 천연기질을 사용하는 경우에서는 실험과정이 보다 단순하여 빠른 방법으로 판정되었다.

• 미생물학회지
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• 제39권1호
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• pp.62-65
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• 2003

폐렴구균의 혈청형 판별법인 multibead assay에서 사용하는 미세구슬 표면에 코팅한 다당류의 안정성을 높이기 위한 방안을 연구하였다. 폐렴구균 피막 다당류 6B에 bovine serum albumin (BSA)을 결합시킨 다당류-단백질 복합체로 코팅했을 경우와 기존의 방법인 다당류만으로 코팅했을 경우의 코팅 효율과 미세구슬표면에서의 6B 안정성을 비교하였다. 다당류 6B-BSA 복합체를 사용했을 경우에 코팅 효율은 약 200 배 증가하였으며, 미세구슬 표면에서의 6B 안정성도 증가하여, 한번 코팅 후 미세구슬을 사용할 수 있는 기간이 3 일에서 30 일 이상으로 연장될 수 있음을 확인하였다.

• Environmental Engineering Research
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• 제25권2호
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• pp.197-204
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• 2020

A number of different nanoscale zero-valent iron (nZVI) materials have been prepared and compared depending on the desired properties for the particular application, but different physicochemical properties of this prepared nZVI make it difficult to universally compare and standardize them to the same scale. In this study, we aimed to demonstrate a simple microplate-based colorimetric assay using 4-chlorophenol as an indicator with respect to the remediation of real treatment targets, such as trichloroethylene (TCE), 1,1,1-trichloroethane (TCA), and atrazine. Effect of nickel contents on 4-chlorophenol reduction was successfully investigated by the miniaturized colorimetric assay. In the same manner, the effect of nickel contents on dehalogenation of TCE, TCA, and atrazine was investigated and the pseudo-first-order kinetic constants were compared with the results for 4-chlorophenol. The similar pattern could be observed between 4-chlorophenol reduction obtained by colorimetric assay and TCE, TCA, atrazine reduction obtained by a traditional chromatographic method. The reaction kinetics does not match perfectly, but the degree of reaction can be estimated. Therefore, the colorimetric assay can be a useful and simple screening tool to determine nZVI reactivity toward halogenated organics before it is applied to a particular remediation site.

• 대한의생명과학회지
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• 제15권4호
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• pp.295-300
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• 2009

Tuberculosis caused by Mycobacterium tuberculosis (MTB) still remains to be the most dreadful infectious disease affecting almost every country. In the present study, we developed a simple and rapid but accurate and sensitive assay method for detecting MTB using microplate hybridization assay. For this, a selective region of the rpoB gene was used to design PCR primers, and MTB and Mycobacterium genus-specific probe molecules. The specificity of the assay was confirmed using fifteen different mycobacterial reference strains and twelve different non-mycobacterial reference strains, and the sensitivity was determined to be 100 fg using genomic DNA of MTB reference strain, H37Rv. Subsequently, a total of 62 sputum samples with diverse smear scores and culture positive results were used to evaluate the kit performance. In brief, the specificity and the sensitivity of the assay were 100% and 98.4%, respectively.

• 동의신경정신과학회지
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• 제17권2호
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• pp.15-36
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• 2006

Objective : This study was designed to assess effect of and Chenwangbosim-Dan(CWBSD) herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation. Mouse neuroblastoma 2a (N2a) cells were treated by CWBSD and herbs. Result : 1. In MTT assay of hypoxia CWBSD and BJI, SJH, IS, CHR, HS among all of herbs were effective. Especially CWBSD and IS were highly effective. 2. In MTT assay of reoxygenation SJI, SJH, VJ, IS, BJI were effective. Especially SJI, SJH, YJ were highly effective. 3. In LDH assay of hypoxia CWBSD, DS, DG, SJH, OMZ were effective. Especially CWBSD, DG were highly effective. 4. In LDH assay of reoxygenation all of herbs except CWBSD and BJI were generally effective. Especially CHR, SJH, YJ, OMZ, HS were highly effective. Conclusion : The results suggest that CWBSD, and it's ingradient(especially SJH, CHR and SJI) may have protective effect on condition of oxidative stress.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.573-577
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• 2013

A loop-mediated isothermal amplification (LAMP) assay allows rapid diagnosis of Toxoplasma gondii infection. In the present study, the LAMP assay was evaluated using blood from both naturally and experimentally infected pigs. The sensitivity of the LAMP assay was compared with that of Q-PCR. Both assays detected T. gondii in the blood of experimentally infected pigs, with 100% agreement. In infected blood samples, the parasite was detected as early as 2 days post-infection and reached a peak in 3-5 days. In 216 field serum samples, the detection rates of LAMP and Q-PCR assays were 6.9% and 7.8%, respectively. This result indicates that the sensitivity of the LAMP assay was slightly lower than that of the Q-PCR assay. However, the LAMP may be an attractive diagnostic method in conditions where sophisticated and expensive equipment is unavailable. This assay could be a powerful supplement to current diagnostic methods.

• Journal of Pharmaceutical Investigation
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• 제39권5호
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• pp.367-372
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• 2009

A rapid liquid chromatography/tandem mass spectrometry (LC/MS/MS) assay method was developed for the determination of topotecan levels in rat serum. The assay utilized a single liquid-liquid extraction with a mixture of ethy l acetate and acetonitrile (6:1 v/v) and isocratic elution. The multiple reaction monitoring was based on the transition of m/z 422.0$\rightarrow$376.5 for topotecan and 315.1$\rightarrow$226.6 for clomipramine (internal standard). The developed assay was validated to demonstrate the specificity, recovery, lower limit of quantification (LLOQ), accuracy and precision. The assay was linear over a concentration range from 0.5-100 ng/mL, with LLOQ being 0.5 ng/mL using a small volume of rat serum (0.1 mL). The mean intra- and inter-day assay accuracy was 87.7-111.0% and 97.8-108.3, respectively, and the mean intra- and interday precision was between 1.6-4.3% and 3.8-10.3, respectively. The developed assay was applied to a pharmacokinetic study after a bolus i.v. injection of topotecan in rats.

• Preventive Nutrition and Food Science
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• 제3권1호
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• pp.27-35
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• 1998

Starch-polyethylene films containing high molecular weight(NW) oxidized-polyethylene and prooxidant were prepared , and thermal -and bio-degradability of the films were determined. Increased levels of starch resulted in a corresponding reduction in mechanical strength of the films. However, the addition of high MW oxidized-polyethylene did not significantly reduce the percent elongation of the films. Thefilms containing high MW oxidized-polyethylene andproosicant were degreaded faster than those containing no aadditive during the heat treatment. The films lost their measureable mechanical properties when their weight-average MW(Mw) fell below 50,000. Biodegradability of the films was determined by a pure culture assay with either Streptomyces badius 252.S. setonii 75Vi2 or S. viridosporous T7A, and by an extracellulr enzyme assay using S. setonii 75vi2. The results from pure culture assay indicated that biomass accumulation on the film surface inhibited chemical and biological degradation of the films. The extracellular enzyme assay demonstrated decrease of percent elongation and increase of carbonyl index of the films. Therefore, extracellular enzyme assay could be used as a good method to evaluate biodegradability of the films.