• KSBB Journal
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• v.22 no.6
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• pp.387-392
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• 2007

Recently, microfluidic biochips for DNA microarray are providing a number of advantages such as, reduction in reagent volume, high-throughput parallel sample screening, automation of processing, and reduction in hybridization time. Particularly, the enhancement of target probe hybridization by decrease of hybridization time is an important aspect highlighting the advantage of microfluidic DNA microarray platform. Fundamental issues to overcome extremely slow diffusion-limited hybridization are based on physical, electrical or fluidic dynamical mixing technology. So far, there have been some reports on the enhancement of the hybridization with the microfluidic platforms. In this review, their principle, performance, and outreaching of the technology are overviewed and discussed for the implementation into many bio-applications.

• Mycobiology
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• v.38 no.1
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• pp.70-73
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• 2010

Temperature-sensitive yeast mutants were used to screen for cell cycle-related genes from Pleurotus eryngii genomic DNA. A mushroom genomic DNA library was established and each gene was screened for the ability to rescue seven Saccharomyces cerevisiae temperature-sensitive strains. Hundreds of yeast transformants were selected at restrictive temperatures over $30^{\circ}C$. Plasmids from the transformants that survived were isolated and transformed back into their host strains. The temperature sensitivity of the resulting transformants was tested from $30^{\circ}C$ to $37^{\circ}C$. Ten DNA fragments from P. eryngii were able to rescue yeast temperature-sensitive strains, and their DNA sequences were determined.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.123-130
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• 2000

The development of inexpensive high throughput methods to identify individual DNA sequences is important to the future growth of medical genetics. This has become increasingly apparent as psychiatric geneticists focus more attention on the molecular basis of complex multifactorial diseases at which most of psychiatric disease is estimated. Furthermore, candidate gene approaches used in identifying disease associated genes necessitate screening large sequence blocks for changes tracking with the disease state. Even after such genes are isolated, large scale mutational analysis will often be needed for risk assessment studies to define the likely medical consequences of carrying a mutated gene. This review provide basic knowledge of up-to-date technology, cDNA microarray which enables above mentioned various research themes.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.118-119
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• 2001

A Southern-hybridization analysis and size-selected DNA library screening led to the isolation of a 6.3-kbp S. setonii DNA fragment, from which the Cl20-encoding genetic locus was found to be located within a 1.4-kbp DNA fragment. A complete nucleotide sequencing analysis of the 1.4-kbp DNA fragment revealed a 0.84-kbp ORF, which showed a strong overall amino acid similarity to the known high－G＋C gram-positive bacterial mesophilic C120s. The heterologous expression of the cloned 1.4-kbp DNA fragment in E. coli demonstrated that this Cl20 possessed a thermophilic activity within a broad temperature range and showed a higher activity against 3-methy1catechol than catechol or 4-methy-catechol, but no activity against protocatecuate.

• The Plant Pathology Journal
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• v.15 no.5
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• pp.295-301
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• 1999

Many of plant defense responses are consequence of transcriptional activation of related genes. We have developed a modified differential screening procedure to isolate tobacco genes that are involved in the defense responses against TMV infection. A cDNA library was constructed from Nicotiana glutinosa leaves infected by TMV under temperature shift conditions. Each of plasmid DNA in the library was hybridized on a set of slot blots to a pool of cDNA probes prepared from either TMV-infected or mock-treated tobacco leaves. Among 900 plasmid DNAs, 81 clones exhibiting significantly enhanced or reduced level of hybridization to either probe were selected for nucleotide sequencing. The clones were listed into 61 genes considering redundancy between the sequences. The genes were identified to be defense-related genes including PR-genes and genes involved in primary or secondary metabolisms. This results supports the implication that plant defense process entails a major shift in total cellular metabolisms rather than activation of a limited number of defense-related genes. Expression patterns of a number of defense-related genes. Expression patterns of a number of selected genes were examined in northern blot analyses. It is notable that the clone 630 of unknown function exhibits expression pattern similar to those of previously known PR-genes. Experiments to elucidate the roles in defense mechanism of a couple of genes newly identified in this study are in progress.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.22 no.1
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• pp.28-36
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• 2022

Purpose: Detection of abnormal metabolites in plasma amino acid (PAA) and urine organic acid (UOA) analyses has been used to diagnose clinical mitochondrial diseases, such as Leigh syndrome. In this study, the diagnostic values and effectiveness of PAA and UOA analyses were reviewed. Methods: This was a retrospective study of patients with Leigh syndrome who were diagnosed between 2003 and 2018 in a single tertiary care center. Through a whole mitochondrial sequencing and nuclear DNA associated mitochondrial gene panel analysis, 19 patients were found to be positive for mitochondrial DNA (mtDNA) mutation-associated Leigh syndrome, and 57 patients were negative. Their PAA and UOA analyses results were then compared. Results: In the comparison of the PAA and UOA analyses results between the two groups, no abnormal metabolites showed obvious differences between the mtDNA mutation-positive Leigh syndrome and mtDNA mutation-negative Leigh syndrome groups. Conclusion: PAA and UOA analyses are inappropriate test methods for diagnosing Leigh syndrome or screening of mtDNA mutation-associated Leigh syndrome. However, UOA analysis might still be a suitable screening test for Leigh syndrome.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5519-5525
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• 2013

Background: Cervical cancer is the second most common cancer in Thai women after breast cancer. Currently, the Papanicolaou (Pap) smear is the recommended procedure for cervical cancer screening in Thailand, but only a relatively small percentage of women follow this screening program. An alternative method to detect HPV genotypes associated with cervical cancer is self-sampling of urine, which is a more widely accepted method. Our study aimed to evaluate the prevalence of HPV in Thai women using urine and cervical swabs and prevalence of HPV in Thai men using urine samples. Materials and Methods: Tumorigenic HPV detection was accomplished by electrochemical DNA chip and PCR/direct sequencing. In addition to HPV prevalence, we report the concordance between different methods and sample types. One-hundred and sixteen women and 100 men were recruited. Histological examination revealed normal cytology in 52 women, atypical squamous cells of undetermined significance (ASCUS) in 9, low-grade squamous intraepithelial lesions (LSIL) in 24, and high-grade squamous intraepithelial lesions (HSIL) in 31. One-hundred men were classified as heterosexuals (n=45) and homosexuals (n=55). Results: The most prevalent HPV genotype in our study was HPV16. The HPV detection rate was generally lower in urine samples compared with cervical samples. Overall, there was good agreement for the detection of carcinogenic HPV from female cervical samples between the DNA chip and PCR/sequencing, with 88.8% total agreement and a kappa value of 0.76. In male urine samples, the level of agreement was higher in heterosexuals compared with homosexuals. Conclusions: Further improvement is required to increase an overall yield of HPV DNA detection in urine samples before clinical application of a urine-based HPV screening program. The electrochemical DNA chip test is a promising technique for carcinogenic HPV detection.

• Journal of Plant Biology
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• v.38 no.4
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• pp.381-388
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• 1995

Four cONA clones expressed in late root nodules of Canavalia lineata were isolated by differential screening using total RNA from uninfected roots, Clb1 and uricase II cONAs as competitors and named Cnod1, Cne2, Cne3 and Clb2, respectively. Cnod1, hybridized to 1450 nt mRNA, was highly homologous to cysteine proteinase gene from rice and showed nodule-specific expression, especially in late nodules. Cne2, hybrdized to 900 nt mRNA, was moderately homologous to Expressed Sequence Tag of rice and expressed mainly in root nodules. Its expression was increased at 13 OAI and subsequently remained at the same level. Cne3, hybridized to 1700 nt and 1400 ot mRNAs, was highly homologous to tonoplast membrane intrinsic protein TRG31 gene from pea and was expressed strongly in roots and nodules, but weakly in leaves. Temporal expression pattern of Cne3 was coincided with the life cycle of root nodules. Clb2, hybridized to 800 nt mRNA, was expressed from 8 OAI, amplified at 13 DAI and remained steady thereafter.eafter.

• Animal cells and systems
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• v.7 no.2
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• pp.159-164
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• 2003

The RAD3 gene of Saccharomyces cerevisiae is required for excision repair and is essential for cell viability. The RAD3 encoded protein possesses a single stranded DNA-dependent ATPase and DNA and DNA-RNA helicase activities. To examine the extent of conservation of structure and function of a S. pombe RAD3 during eukaryotic evolution, the RAD3 homolog gene was isolated by screening of genomic DNA library. The isolated gene was designated as HRD3 (homolog of RAD3 gene). Southern blot analysis confirmed that S. pombe chromosome contains the same DNA as HRD3 gene and this gene exists as a single copy in S. pombe. The transcript of 2.8 kb was detected by Northern blot analysis, The level of transcripts increased by ultraviolet (UV) irradiation, indicating that HRD3 is one of the UV-inducible genes in S. pombe. Furthermore, the predicted partial sequence of HRD3 protein has 60％ identity to S. cerevisiae RAD3 gene. This homology was particularly striking in the regions identified as being conserved in a group of DNA helicases. Gene deletion experiments indicate that the HRD3 gene is essential for viability and DNA repair function. These observations suggest evolutionary conservation of other protein components with which HRD3 might interact in mediating its DNA repair and viability functions.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.450-455
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• 1996

The genomic DNA was prepared from trout liver which was treated with 3-methycholanthrene, and cloned into lambda EMBL3 at BamHl site. The genomic library was constructed via infections of these recombinant phages into E. coli K802, and screened by the most $5^I$-portion of trout CYP1A1 cDNA. After the screening of $10^9$ clones of the amplified library, 12 positive clones were isolated, and subjected to further screenings. The results of southern blot hybridization of genomic DNA prepared from the positive clone showed the presence of a single gene of CYP1A1, and 3.5 Kb PstI fragment that hybridizes with the most $5^I$-region DNA of CYP1A1 cDNA. The restriction map of PstI fragment was determined by the restriction digestion with various enzymes. The nucleotide sequence of the upstream genomic DNA of CYPIAI was determined by DNA sequencing of exonuclease III unidirectionally deleted PstI fragment DNA using $[^{35}/S]$dATP. This paper presented the upstream genomic DNA of CYP1A1 contained a part of coding region which was about 351 base pairs (from ATG to PstI site at 3563).