• Journal of Microbiology
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• v.41 no.3
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• pp.252-258
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• 2003

The carbon utilizations of Bacillus species and Pythium species were investigated by using a Biolog$^{(R)}$ microplate assay to determine if there are differences in the carbon utilizations of selected strains of these species. It may be possible to afford a competitive advantage to bacterial biological control agents by providing them with a substrate that they can readily use as a carbon source, for example, in a seed coating formulation. Microplates, identified as SFP, SFN and YT were used to identify spore-forming bacteria, nonspore-forming bacteria, and yeast, respectively. Bacterial and mycelial suspensions were adjusted to turbidities of 0.10 to 0.11 at 600 nm. One hundred microliters of each of the bacterial and mycelial suspension were inoculated into each well of each of the three types of microplates. L-arabinose, D-galactose, D-melezitose and D-melibiose of the 147 carbohydrates tested were found to be utilized only by bacteria, and not by Pythium species, by Biolog$^{(R)}$ microplate assay, and this was confirmed by traditional shake flask culture. Thus, it indicated that the Biolog$^{(R)}$ microplate assay could be readily used to search for specific carbon sources that could be utilized to increase the abilities of bacterial biological control agents to adapt to contrived environments.

• BMB Reports
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• v.36 no.3
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• pp.332-335
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• 2003

Cytochrome P450 in microsomes can be quantitated using the characteristic 450 nm absorption peak of the CO adduct of reduced cytochrome P450. We developed a simple microplate assay method that is superior to previous methods. Our method is less laborious, suitable for analyzing many samples, and less sensitive to sample aggregation. Microsome samples in microplate wells were incubated in a CO chamber rather than bubbled with CO gas, and then reduced with sodium hydrosulfite solution. This modification allowed a reliable and reproducible assay by effectively eliminating variations between estimations.

• BMB Reports
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• v.36 no.4
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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.

• Korean Journal of Pharmacognosy
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• v.28 no.3
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• pp.131-137
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• 1997

The aqueous and methanolic extracts of 110 crude drugs were screened for hyaluronidase inhibitory activity using a microplate assay. Among them, MeOH extract of 15 crude drugs inhibited more than 80% of hyauluronidase activity at the concentration of 5mg/ml. The active principles of Anemarrhenae Rhizoma, Rhei Rhizoma, Ephedrae Herba, Pteropi Faeces and Ginseng Radix alba were transferred into organic solvents.

• BMB Reports
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• v.42 no.2
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• pp.81-85
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• 2009

Early and accurate detection of drug resistant Mycobacterium tuberculosis can improve both the treatment outcome and public health control of tuberculosis. A number of molecular-based techniques have been developed including ones using probe molecules that target drug resistance-related mutations. Although these techniques are highly specific and sensitive, mixed signals can be obtained when the drug resistant isolates are mixed with drug susceptible isolates. In order to overcome this problem, we developed a new drug susceptibility test (DST) for one of the most effective anti-tuberculosis drug, isoniazid. This technique employed a microplate hybridization assay that quantified signals from each probe molecule, and was evaluated using clinical isolates. The evaluation analysis clearly showed that the microplate hybridization assay was an accurate and rapid method that overcame the limitations of DST based on conventional molecular techniques.

• Korean Journal of Community Nutrition
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• v.4 no.4
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• pp.512-520
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• 1999

Microbiological method using a 96-well microplate reader for folate assay was established, and folate intake and blood folate concentrations of 23 female college students were assessed. To evaluate folate intake, dietary data were collected by a 3-day weight food record, and serum and RBC folate concentrations were measured by the new method. The coefficient of variation for the new method was less than 10%. Mean daily folate intake of the subjects was 126.7${\mu}g$ which is only 50.7% of the RDA. The mean concentrations of serum and RBC folate were 7.46ng/ml and 294.4ng/ml, respectively, which were within the normal range. These results indicate that folate intake seems to be underestimated due to incomplete food composition database. Therefore, folate database should be appropriately in order to asses folate intake accurately.

• Biomedical Science Letters
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• v.15 no.4
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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.

• Korean Journal of Animal Reproduction
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• v.17 no.4
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• pp.347-356
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• 1994

A simpled and sensitive microplate enzyme immunoassay(EIA) was developed for the determination of progesterone concentration in serum, based on progesterone monoclonal antibody as anti-progesterone, horseradish peroxidase(HRP) as enzyme-label and tetramethylbenzidine(TMB) as substrate. The assay has a sensitivity of 5 pg-120pg/well and intra- and inter-assay coefficients of variation for progesterone standard curve (1.0ng~10.0ng/ml) were ranged 2.5~9.9% and 1.7.8.0%, respectively, determination coefficient of the regressio equation of our standard curve(R2=0.990$\pm$0.007) were high, and this is the same level as that of commercial kit(Hormonost Bio-Lab, Germany, R2=0.98~0.99). The progesterone concentration of serum determined by both kits (Work & Bio-Lab) were significantly correlated (r=0.95, P<0.01) although a little higher value were resulted in our kit than that of commercial kit. It generally is these results indicated that the microplate-EIA can be cused for the determination of progesterone in serum, as well as, for the determination of the early pregnancy diagnosis.

• Korean Journal of Pharmacognosy
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• v.32 no.3 s.126
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• pp.253-256
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• 2001

The present study was designed for the improvement of routine measurement of superoxide and hydroxyl radical scavenging activities utilized by a microplate reader. Superoxide radical scavenging activity by the ascorbic acid, which is a well-known superoxide scavenger, was determined in a dose-dependent manner. Hydroxyl radical scavenging activity by the thiourea, which is a well-known hydroxyl radical scavenger, was also well detected in a dose-dependent manner. Our results suggest that the use of microplate reader to assay the superoxide and hydroxyl radical scavenging activities improves the accuracy of data and enables the use of much smaller amounts of samples and/or reagents, with much simpler experimental procedure. Therefore, These methods appear to be suitable for screening of superoxide and hydroxyl radical scavenging activities in both the plant medicinal extracts and the isolated compounds.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.149-149
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• 2005