• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1141-1146
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• 2018

2'-Fucosyllactose (2'-FL) is one of the most important human milk oligosaccharides and has several health benefits for infants. The levels of 2'-FL in breast milk or samples from other sources can be quantified by high-performance liquid chromatography. However, this method cannot be used for simultaneous detection of the target compound in numerous samples. Here, we developed a simple method for quantifying 2'-FL in a microplate format. The method involves two steps: (i) release of $\text\tiny{L}$-fucose from 2'-FL by ${\alpha}$-(1-2,3,4,6)-$\text\tiny{L}$-fucosidase and (ii) measurement of NADPH formed during the oxidation of $\text\tiny{L}$-fucose by $\text\tiny{L}$-fucose dehydrogenase. This method enables measurement of up to 5 g/l 2'-FL in 50 min using a 96-well microplate. The efficiency and simplicity of the proposed method make it suitable for the analyses of a large number of samples simultaneously.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.72-77
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• 1999

To investigate soil bacterial diversity according to vegelalioo types, utilizing ability of sole carbon sources and restriction enzyme patterns of 16s rDNA were analyzed. From the both results; five kinds of soil microbial communities were grouped as forest soil (Quercus mongolica and Pinus densi&ra vegetation), grass-agricultured soil and microbial communities of naked soil. But, both soil microbial communities of directily exlracted from ths soil and indirectly extracted from heterotrophic bacteria that cultured soil in LB medium showed very different similarity.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.65-71
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• 1999

This study was carried out utilzing ability of sole carbon sources in soil microbial communities used by Biolog GN microplate. Cluster analysis showed that soil microbial cornmuties were categorized into three groups as forest, non-forest soil and naked soil of microbial group. Soil microbial commutites in a forest soil of Qirercus mongoIica was divided into another group microbial communites in Qirercus dendata vegetation soil and Pinus dnzsqlora vegetation soil by Multidimensional scaling(MDS). Generally, sole carbon utilzing abilties were higher in order of polymer, amino acids and carboxylic acids, but it was lower in amides substrates carbon group. From the result: it was supposed that metabolic diversity of microbial communities was corresponded to vegetation succession.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.141-149
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• 2017

Due to the inaccuracy of micro-machining, various special processing methods have been investigated recently. Among them, pulse electrochemical machining is a promising machining method with the advantage of no residual stress and thermal deformation. Because the cross section of the wire electrode used in this study is circular, wire-pulse electrochemical machining is suitable for micro-hole machining. By applying the response surface methodology, the experimental plan was made of three factors and three levels: machining time, duty factor, and voltage. The regression equation was obtained through experiments. Then, by referring to the main effect diagram, we fixed the duty factor and machining time with little relevance, and solved the equation for the target 900 microns to obtain the voltage value. The results obtained from the response surface methodology were approximately those of the target value when the actual experiment was carried out. Therefore, it is concluded that the optimal conditions for hole processing can be obtained by the response surface methodology.

• Biomedical Science Letters
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• v.3 no.2
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• pp.107-114
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• 1997

Recent reports indicate that the clinical usefulness of prostate specific antigen (PSA), particulary in the differentiation of benign prostate hyperplasia from prostate cancer, can be improved by measuring the amount of free PSA in serum. Measuring free PSA is especially useful in attempts to improve diagnositc performance of PSA in the diagnostic gray zone of total PSA. The objective of this study was to develop free PSA assay kit using sandwich microplate enzyme immunoassay format. We chose a test format with polyclonal anti-PSA antibodies coated on the wells and monoclonal anti-free PSA antibodies for quantification to gain higher test sensitivity. We adpoted 10 uL of specimen and 2 hours of first incubation time with detecting antibody for free PSA EIA format using microplate. The within-day and between-day precision (%CV) in the high and low concentration ranges were below 4%. The correlation coefficient between in-house free PSA assay and commercial assay kit was r=0.9965 (slope=0.0984, y intercept=0.0173, N=27). No hook effect was found by 40 ng/mL and correlation coefficient (r) value of the fitted linear regression was over 0.995. The recovery tests were in the range of 98.9∼104.1％ for free PSA. In conclusion, in-house free PSA enzyme immune assay is cost effective, simple and rapid and could be useful for the prognosis after theraphy as well as for the differential diagnosis between prostate cancer and benign prostate hyperplasia.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.308-314
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• 2015

This study was conducted to establish a fluorescence assay system for high efficient mass screening of the herbicides causing rapid membrane peroxidation, based on the fact that peroxide in cellular leakage could be fluorometrically determined through the fuorescent compounds formed after reacting with homovanillic acid (HVA) and peroxidase (HRP). The assay procesure established in this study was as follows. Only single disc (4 mm diameter) excised from cucumber cotyledon is placed on the well containing test solution ($200{\mu}L$) with 96-well microplate. The plate is shaking-incubated for 8 h under light condition. Then after removing the cucumber disc, HVA and HRP are supplied in the medium buffer and incubated for 5 min at room temperature. Fluorescence values are determined at Ex 320 nm/Ex 425 nm. The higher fluorescence values are obtained in the treatment of chemical having higher herbicidal activity. Using this assay with 96-well microplates, a large number of herbicides inducing rapid membrane peroxidation seemed to be screened more efficiently than spectrophotometric microtiter assay reported previously.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.09a
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• pp.108-108
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• 2005

• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.41-46
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• 2001

This study was conducted to develop a high throughput system for screening acetolactate synthase(ALS) inhibitors, and to detect basic mother molecules for developing new novel herbicide candidates. The high throughput screening (HTS) method using 96-well plate and microplate reader was developed. This method is 8 times more effective than basic technique in one cycle per person. Futhermore, considering for less than 1/10 volume of materials required for ALS test and enzyme kinetics with 16 times faster speed compared to those of former procedure, this HTS method has more than 100 times higher efficacy than basic system in a consecutive procedure. We discovered 11 new ALS inhibitors such as 2-oxoglutaric acid, aminooxyacetic acid, azelaic acid, citric acid, cyanuric fluoride, itaconic acid, malonic acid, niclosamide, oxalic acid, glyoxylic acid, and suramin from 107 commercial plant-specific inhibitors using this technique. We hope these results might be useful to discover lead compounds for developing new novel herbicide candidate.

• The Journal of the Korean Society for Microbiology
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• v.20 no.1
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• pp.25-34
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• 1985

Species of scotochromogenic mycobacteria of Group II isolated from sputa of patients with pulmonary tuberculosis and tuberculosis-like diseases from 1979 to 1984 were identified by simple biochemical tests using. nitrate reduction, Tween-80 hydrolysis, arylsulfatase and urease test, and serotypes of the isolates belonging to M. scrofulaceum were differentiated by bacterial agglutination test. Of 39 strains. tested, 11(28.2%) proved to be M. scrofulaceum, 15(38.5%) M. flavescens and 13(33.3%) M. gordonae. But none of the isolates belonged to M. szulgai and M. xenopi known as major pathogens of mycobacteria of Group II. Of 11 strains of the isolates identified as M. scrofulaceum 3 strains(27.3%) each belonged to serotype 41 and 42, and 4 strains(36.4%) belonged to serotype 43, but one strain was not typable because of its inagglutinability by any one of the type specific sera. In addition, the sensitivity and specificity of rabbit immune sera against type strains of serotype 41, 42 and 43 of M. scrofulaceum were analysed by bacterial agglutination test. In the sensitivity of microplate test with 11 isolates of M. scrofulaceum, a comparative tandem test using 2 units and one unit of absorbed antisera against three serotypes appeared to be superior to a conventional microplate test using one unit of type specific antisera.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.195-199
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• 1983

A microplate enzyme-linked immunosorbent assay (ELISA) for detecting antibodies to bovine leukemia virus(BLV) is described and compared its sensitivity with that of the agar gel immunodiffusion test (ID) with BLV glycoprotein (gp) antigen using 263 sera collected in Korea and Japan. There was 98.5 per cent agreement between ELISA and ID when ELISA value, the value of tested serum(T) was devided with that of standard negative seurm(N) after the value of control was eliminated from T and N (T-C/N-C), of 1.5 or greater was considered positive. One hundred and forty four (99.6%) of 145 sera which were positive by ID were greater than 1.5 by ELISA, and 115 (97.5%) of 118 sera which were negative by ID were less than 1.5 by ELISA. As a result, it suggest that the ELISA test using BLV-gp antigen provides a useful serological tool for the diagnosis of BLV infection.