Publications by authors named "Dong Hyuck Lee"

3 Publications

  • Page 1 of 1

Quantitative detection of residual E. coli host cell DNA by real-time PCR.

J Microbiol Biotechnol 2010 Oct;20(10):1463-70

Department of Biological Sciences, Hannam University, Daejon 305-811, Korea.

E. coli has been widely used as a host system to manufacture recombinant proteins for human therapeutic use. Among impurities to be eliminated during the downstream process, residual host cell DNA is a major interest for safety. Residual E. coli host cell DNA in the final products are usually determined using conventional slot blot hybridization assay or total DNA Threshold assay, although these methods are time consuming, expensive, and relatively insensitive. Therefore a sensitive real-time PCR assay for specific detection of residual E. coli DNA was developed and compared with slot blot hybridization assay and Threshold assay to validate the overall capability of these methods. Specific primer pair for amplification of the E. coli 16S rRNA gene was selected to improve the sensitivity, and E. coli host cell DNA was quantified by use of SYBR Green 1. The detection limit of real-time PCR assay in the optimized condition was calculated to be 0.042 pg genomic DNA, which is much higher than those of slot blot hybridization assay and Threshold assay of which detection limit were 2.42 and 3.73 pg genomic DNA, respectively. The real-time PCR assay was validated to be more reproducible, accurate, and precise than slot blot hybridization assay and Threshold assay. The real-time PCR assay may be a useful tool for quantitative detection and clearance validation of residual E. coli DNA during the manufacturing process for recombinant therapeutics.
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http://dx.doi.org/10.4014/jmb.1004.04035DOI Listing
October 2010

Gramella echinicola gen. nov., sp. nov., a novel halophilic bacterium of the family Flavobacteriaceae isolated from the sea urchin Strongylocentrotus intermedius.

Int J Syst Evol Microbiol 2005 Jan;55(Pt 1):391-394

Department of Biological Sciences, Hannam University, 133 Ojung-Dong, Daeduk, Daejon 306-791, Republic of Korea.

A novel marine bacterium, strain KMM 6050T, was isolated from the sea urchin Strongylocentrotus intermedius, which inhabits the Sea of Japan. The strain studied was strictly aerobic, heterotrophic, yellow-orange-pigmented, motile by gliding, Gram-negative and oxidase-, catalase-, beta-galactosidase- and alkaline phosphatase-positive. The results of 16S rRNA gene sequence analysis showed that strain KMM 6050T occupies a distinct lineage within the family Flavobacteriaceae and is most closely related to the species Mesonia algae and Salegentibacter salegens (sequence similarity of 92.5-92.6 %). The DNA G+C content of KMM 6050T was 39.6 mol%. The major respiratory quinone was MK-6. The predominant fatty acids were i15 : 0, a15 : 0, 15 : 0, i16 : 1, i16 : 0, i16 : 0 3-OH and i17 : 0 3-OH. On the basis of phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, the novel bacterium has been assigned to the genus Gramella gen. nov., as Gramella echinicola sp. nov. The type strain is KMM 6050T (=KCTC 12278T=NBRC 100593T=LMG 22585T).
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http://dx.doi.org/10.1099/ijs.0.63314-0DOI Listing
January 2005

Roseivirga ehrenbergii gen. nov., sp. nov., a novel marine bacterium of the phylum 'Bacteroidetes', isolated from the green alga Ulva fenestrata.

Int J Syst Evol Microbiol 2005 Jan;55(Pt 1):231-234

Korean Collection for Type Cultures, Biological Resources Center, Korea Institute of Bioscience and Biotechnology, Yusong, Daejon 305-333, Republic of Korea.

The taxonomic position of a novel marine bacterium isolated from the green alga Ulva fenestrata collected in the Sea of Japan was established. Cells of the strain studied, designated KMM 6017T, were strictly aerobic, heterotrophic, pink-pigmented, non-motile by gliding, Gram-negative and oxidase-, catalase-, beta-galactosidase- and alkaline phosphatase-positive. 16S rRNA gene sequence analysis indicated that the strain occupied a distinct lineage within the phylum 'Bacteroidetes' and formed a cluster with [Flexibacter] tractuosus and Reichenbachia agariperforans. The G+C content of the DNA of KMM 6017T was 40.2 mol%. The major respiratory quinone was MK-7. The predominant fatty acids were i15 : 1, i15 : 0 and i17 : 0 3-OH (34.2, 24 and 7.7 %, respectively). On the basis of phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, the novel bacterium was assigned to the genus Roseivirga gen. nov., as Roseivirga ehrenbergii gen. nov., sp. nov. The type strain is KMM 6017T (=KCTC 12282T=LMG 22567T).
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http://dx.doi.org/10.1099/ijs.0.63341-0DOI Listing
January 2005
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