• Title/Summary/Keyword: Fluorescence-based assay

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Recent Development of Protein Microarray and Proteogen Platform

  • Han, Moon-Hi;Kang, In-Cheol;Lee, Yoon-Suk;Cho, Yong-Wan;Lee, Eun-Kyoung
    • 한국생물공학회:학술대회논문집
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    • 2005.04a
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    • pp.47-47
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    • 2005
  • There are many different surface technologies currently applied for preparation of protein chips. However, it requires innovative surface chemistry for capture proteins to be immobilized on chip surface keeping their conformation and activity intact and their orientation right, while they bind tightly and densely in a given array spot. Proteogen has developed 'ProteoChip BP' coated with novel proprietary linker molecules $(ProLinker^{TM})$ for efficient and robust immobilizations of capture proteins by improving surface properties of molecular captures. It was demonstrated that $ProLinker^{TM}$ gave the best surface performance in preparation of protein microarray chip base plates among others currently available on the market. In particular, the $ProLinker^{TM}-based$ surface chemistry has demonstrated to provide excellent performance in preparation of 'Antibody Chip' for analysis of biomarkers as well as proteome expression profiles. The linker molecule has also shown to be well applicable for development of biosensors and micro-beads as well as protein microarray and nano-array. ProteoChip BP can be used either for preparation of high-density array by using a microarrayer or for preparation of 'Well-on-a-Chip' with low density array, which is better applicable for quantitative analysis of biomarkers or protein-protein interactions. The biomarker assay can be performed either by direct or sandwich methods of fluorescence immunoassay. Application of ProteoChip BP has been well demonstrated by the extensive studies of 1) tumor-marker assays, 2) new drug screening by using 'Integrin Chip' and 3) protein expression profile analysis. Some of experimental results will be presented.

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High-throughput SNP Genotyping by Melting Curve Analysis for Resistance to Southern Root-knot Nematode and Frogeye Leaf Spot in Soybean

  • Ha, Bo-Keun;Boerma, H. Roger
    • Journal of Crop Science and Biotechnology
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    • v.11 no.2
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    • pp.91-100
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    • 2008
  • Melting curve analysis of fluorescently labeled DNA fragments is used extensively for genotyping single nucleotide polymorphism(SNP). Here, we evaluated a SNP genotyping method by melting curve analysis with the two probe chemistries in a 384-well plate format on a Roche LightCycler 480. The HybProbe chemistry is based on the fluorescence resonance energy transfer(FRET) and the SimpleProbe chemistry uses a terminal self-quenching fluorophore. We evaluated FRET HybProbes and SimpleProbes for two SNP sites closely linked to two quantitative trait loci(QTL) for southern root-knot nematode resistance. These probes were used to genotype the two parents and 94 $F_2$ plants from the cross of PI 96354$\times$Bossier. The SNP genotypes of all samples determined by the LightCycler software agreed with previously determined SSR genotypes and the SNP genotypes determined on a Luminex 100 flow cytometry instrument. Multiplexed HybProbes for the two SNPs showed a 98.4% success rate and 100% concordance between repeats two of the same 96 DNA samples. Also, we developed a HybProbe assay for the Rcs3 gene conditioning broad resistance to the frogeye leaf spot(FLS) disease. The LightCycler 480 provides rapid PCR on 384-well plate and allows simultaneous amplification and analysis in approximately 2 hours without any additional steps after amplification. This allowed for a reduction of the potential contamination of PCR products, simplicity, and enablement of a streamlined workflow. The melting curve analysis on the LightCycler 480 provided high-throughput and rapid SNP genotyping and appears highly effective for marker-assisted selection in soybean.

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Evaluation of Transferrin-Polyethylenimine Conjugate for Targeted Gene Delivery

  • Lee Kyung Man;Kim In Sook;Lee Yong Bok;Shin Sang Chul;Lee Kang Choon;Oh In Joon
    • Archives of Pharmacal Research
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    • v.28 no.6
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    • pp.722-729
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    • 2005
  • With the aim to improve the specificity and to reduce the cytotoxicity of polyethylenimine (PEI), we have synthesized the conjugates of the branched PEI (25 kDa) with transferrin. The trans-ferrin-PEI (TP) conjugates with five compositions were synthesized using periodate oxidation method and confirmed by FT-IR spectroscopy and gel permeation chromatography. The free amine contents of TP conjugates, which were able to condense and deliver DNA, increased as the amount of PEI increased. TP/DNA polyplexes were characterized by measuring gel elec-trophoresis, ethidium bromide fluorescence quenching, particle size and zeta potential of complexes. Complete complexation of the polyplexes was observed above the N/P ratio of 5 in TP/DNA, and above 3 in PEI/DNA, respectively. The zeta potential of the complexes decreased as the amount of transferrin in TP conjugates increased. Transfection efficiency of TP conjugates was evaluated in HeLa cell and Jurkat cell systems. Among the five compositions of TP conjugates, TP-2 system mediated a higher $\beta$-galactosidase gene expression than PEI system in Jurkat cell which was known to express elevated numbers of transferrin receptors. From the results of the cell viability based on MTT assay, TP conjugates showed lower cytotoxicity com-pared with the PEI system. We expect that the TP conjugate can be used efficiently as a non-viral gene delivery vector.

Biapigenin, Candidate of an Agonist of Human Peroxisome Proliferator-Activated Receptor γ with Anticancer Activity

  • Kim, Jin-Kyoung;Shin, So-Young;Lee, Jee-Young;Lee, So-Jung;Lee, Eun-Jung;Jin, Qinglong;Lee, June-Young;Woo, Eun-Rhan;Lee, Dong-Gun;Yoon, Do-Young;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2717-2721
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    • 2011
  • Peroxisome proliferator-activated receptors (PPARs) are a subfamily of nuclear receptors (NRs). Human peroxisome proliferator-activated receptor gamma (hPPAR${\gamma}$) has been implicated in the pathology of numerous diseases, including obesity, diabetes, and cancer. ELISA-based hPPAR${\gamma}$ activation assay showed that biapigenin increased the binding between hPPAR${\gamma}$ and steroid receptor coactivator-1 (SRC-1) by approximately 3-fold. In order to confirm that biapigenin binds to hPPAR${\gamma}$, fluorescence quenching experiment was performed. The results showed that biapigenin has higher binding affinity to hPPAR${\gamma}$ at nanomolar concentrations compared to indomethacin. Biapigenin showed anticancer activity against HeLa cells. Biapigenin was noncytotoxic against HaCa T cell. All these data implied that biapigenin may be a potent agonist of hPPAR${\gamma}$ with anticancer activity. We will further investigate its anticancer effects against human cervical cancer.

Concatemer-Associated Transgene Expression Patterns in Transgenic Marine Medaka Oryzias dancena Strains

  • Cho, Young Sun;Kim, Dong Soo;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.18 no.1
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    • pp.73-80
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    • 2015
  • To examine the interrelationship between transgenic insertion patterns and transgene expression profiles in established transgenic fish lines, four stable transgenic marine medaka Oryzias dancena germlines harboring ${\beta}$-actin regulator-driven RFP reporter constructs were selected. The established transgenic strains were characterized with regard to their transgenic genotypes (insertion pattern, concatemer formation, and transgene copy number based on genomic Southern blot hybridization and qPCR assay) and expression characteristics at the mRNA (qRT-PCR), protein (western blot), and phenotypic (fluorescent appearance) levels. From comparative examinations, it was found that transgenic expression at both the transcription and translation levels could be significantly downregulated in transgenic strains, potentially through methylation-mediated transgene silencing that was particularly associated with the formation of a long tail-to-head tandem concatemer in the chromosomal integration site(s). When this occurred, an inverse relationship between the transgene copy number and fluorescence intensity was observed in the resultant transgenic fish. However, with the other transgenic genotype, transgenic individuals with an identical Southern blot hybridization pattern, containing a tandem concatemer(s), had very different expression levels (highly robust vs. low expression strengths), which was possibly related to the differential epigenetic modifications and/or degrees of methylation. The concatemer-dependent downregulation of transgene activity could be induced in transgenic fish, but the overall pattern was strain-specific. Our data suggest that neither a low (or single) transgene copy number nor tandem transgene concatemerization is indicative of strong or silenced transgene expression in transgenic fish carrying a ubiquitous transgene. Hence, a sufficient number of transgenic lineages, with different genotypes, should be considered to ensure the establishment of the best-performance transgenic line(s) for practical applications.

Low Level of TERC Gene Amplification between Chronic Myeloid Leukaemia Patients Resistant and Respond to Imatinib Mesylate Treatment

  • Mohamad Ashari, Zaidatul Shakila;Sulong, Sarina;Hassan, Rosline;Husin, Azlan;Sim, Goh Ai;Wahid, S. Fadilah Abdul
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.4
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    • pp.1863-1869
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    • 2014
  • The amplification of telomerase component (TERC) gene could play an important role in generation and treatment of haematological malignancies. This present study was aimed to investigate copy number amplification status of TERC gene in chronic myeloid leukaemia (CML) patients who were being treated with imatinib mesylate (IM). Genomic DNA was extracted from peripheral blood of CML-IM Resistant (n=63), CML-IM Respond (n=63) and healthy individuals (n=30). TERC gene copy number predicted (CNP) and copy number calculated (CNC) were determined based on $Taqman^{(R)}$ Copy Number Assay. Fluorescence in situ hybridization (FISH) analysis was performed to confirm the normal signal pattern in C4 (calibrator) for TERC gene. Nine of CML patients showed TERC gene amplification (CNP=3), others had 2 CNP. A total of 17 CML patients expressed CNC>2.31 and the rest had 2.31>CNC>1.5. TERC gene CNP value in healthy individuals was 2 and their CNC value showed in range 1.59-2.31. The average CNC TERC gene copy number was 2.07, 1.99 and 1.94 in CML-IM Resistant patients, CML-IM Respond and healthy groups, respectively. No significant difference of TERC gene amplification observed between CML-IM Resistant and CML-IM Respond patients. Low levels of TERC gene amplification might not have a huge impact in haematological disorders especially in terms of resistance towards IM treatment.

Production of Monoclonal Antibodies (Mabs) Against Surface Antigens on Israeli Carp Lymphocytes and Their Applications

  • Woo, Jong-Kyu;Jang, Han-Na;Cho, Young-Hye;Jang, Yong-Suk;Choi, Sang-Hoon
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.8
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    • pp.1179-1187
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    • 2001
  • In fish both humoral and cell mediated immune responses have been reported whereas antibodies recognizing specific cellular populations have not yet been developed except for ones recognizing surface Ig molecules on B lymphocytes. Our aim was to develop and characterize monoclonal antibodies (Mabs) specific for the immune-related cells. Mabs were produced by fusion of myeloma cells (SP2/0) with Balb/c mouse spleen cells previously sensitized against Israeli carp (I. carp) kidney mononuclear cells. We obtained 44 Mabs positively reacting with I. carp kidney mononuclear cells and partially characterized 7 Mabs in the morphological and mitogen-based proliferative aspects. Fluorescence-activated cell sorter (FACS) analysis against I. carp kidney cells by using 7 different Mabs showed 80.3% for ICK 17-4, 65.1% for ICK 2-3, 64.1% for ICK 25-1, 67.5% for lCK 22-1, 70.8% for ICK 16-2, 76.8% for ICK 13-2, 79.7% for ICK II-I. Panning method was used for the isolation of Mabs specific mononuclear carp spleen cells followed by Wright's stain. The stained cell populations were identified as monocytes (ICK 17-4, ICK 2-3, ICK 25-1, ICK 22-1 and ICK 16-2), lymphocytes (ICK 11-1), and a mixed cell population of monocytes and lymphocytes (ICK 13-2). In cell proliferation assay, monocytes purified by ICK 17-4, 2-3 and 22-1 efficiently responded to Con A and PHA, while ones separated by ICK 25-1 did not react with any mitogens. Lymphocytes isolated by ICK 11-1, though it is not known whether they are T or B cells, were more responsive to Con A than PHA or LPS, suggesting that fish immune cells are somewhat different from mammalian cells in responding to mammalian T or B cell mitogens.

Development and Characterization of a Novel Anti-idiotypic Monoclonal Antibody to Growth Hormone, Which Can Mimic Physiological Functions of Growth Hormone in Primary Porcine Hepatocytes

  • Lan, Hai-Nan;Jiang, Hai-Long;Li, Wei;Wu, Tian-Cheng;Hong, Pan;Li, Yu Meng;Zhang, Hui;Cui, Huan-Zhong;Zheng, Xin
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.4
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    • pp.573-583
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    • 2015
  • B-32 is one of a panel of monoclonal anti-idiotypic antibodies to growth hormone (GH) that we developed. To characterize and identify its potential role as a novel growth hormone receptor (GHR) agonist, we determined that B-32 behaved as a typical $Ab2{\beta}$ based on a series of enzyme-linked immunosorbent assay assays. The results of fluorescence-activated cell sorting, indirect immunofluorescence and competitive receptor binding assays demonstrated that B-32 specifically binds to the GHR expressed on target cells. Next, we examined the resulting signal transduction pathways triggered by this antibody in primary porcine hepatocytes. We found that B-32 can activate the GHR and Janus kinase (2)/signal transducers and activators of transcription (JAK2/STAT5) signalling pathways. The phosphorylation kinetics of JAK2/STAT5 induced by either GH or B-32 were analysed in dose-response and time course experiments. In addition, B32 could also stimulate porcine hepatocytes to secrete insulin-like growth factors-1. Our work indicates that a monoclonal anti-idiotypic antibody to GH (B-32) can serve as a GHR agonist or GH mimic and has application potential in domestic animal (pig) production.

An Immunoserological Study of Vaccine Against Haemorrhagic Fever with Renal Syndrome (신증후출혈열 백신의 면역혈청학적 연구)

  • Woo, Young-Dae;Chu, Yong-Kyu;Baek, Luck-Ju;Lee, Ho-Wang
    • The Journal of Korean Society of Virology
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    • v.30 no.1
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    • pp.11-18
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    • 2000
  • Since $Hantavax^{TM}$, formalin inactivated Hantaan virus vaccine (10,240 ELISA units/ml), has been developed in 1990 to prevent against haemorrhagic fever with renal syndrome (HFRS) caused by Hantaan or Seoul virus, it has been commercially available in Korea. Twenty-one healthy people were booster shot once and twice after primary basic vaccination with $Hantavax^{TM}$. Seroconversion rates were measured by immunofluorescent antibody technique (IFAT), enzyme-linked immunosorbent assay (ELISA), high density composite particle agglutination (HDPA), and plaque reduction neutralization test (PRNT). Seroconversion rates of 21 vaccinees at one year after primary basic vaccination were 52.3%, 95.2%, 0.0%, 47.6%, and 28.6%, and 13 vaccinees at one month after 1st booster vaccination were 100%, 100%, 30.7%, 100% and 100% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates declined slightly by twenty months, and they were 84.6%, 92.3%, 0.0%, 84.6% and 69.2% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates of 9 vaccinees at three months after 2nd booster vaccination were 100%, 100%, 0.0%, 100%, and 88.9%, and 16 vaccinees at one year after the 2nd booster vaccination were 87.5%, 93.8%, 0.0%, 87.5% and 81.3% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Based on the above result $Hantavax^{TM}$ has proved a vigorous anamnestic response after the 1st and the 2nd booster vaccination and has persisted higher fluorescence, agglutination and neutralizing antibody titers in vaccinees.

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The Etiologic Roles and Carcinogenic Mechanisms of Human Papilloma Virus in Head and Neck Squamous Cell Carcinoma (두경부 편평세포암종의 발암 원인으로 인간유두종 바이러스(Human Papilloma Virus)의 역할 및 이와 관련된 발암 기전에 관한 연구)

  • Shin, Dong-Hyun;Lee, Sei-Young;Koo, Bon-Seok;Kim, Se-Heon
    • Korean Journal of Head & Neck Oncology
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    • v.25 no.1
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    • pp.28-32
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    • 2009
  • Background : The most frequently reported risk factors for head and neck suamous cell carcinoma are smoking and alcohol. But in a recent overview, human papilloma virus(HPV) infection was revealed the important carcinogenic factor in oropharyngeal cancer. We aimed to clarify whether HPV directly effects on the oncogenesis and biologic behavior of hean and neck squamous cell carcinoma by comparison with infection prevalence, and physical status of virus. Material and Method : We used HPV genotyping DNA chip(Biocore, Korea, Seoul) arrayed by multiple oligonucleotide probes of L1 sequence of 26 types of HPV and HPV genotypes are identified by fluorescence scanner. The copy numbers of HPV E2 and E6 open reading frames(ORF) were assessed using a TaqMan-based 5'-exonuclease quantitative real-time PCR assay. The ratio of E2 to E6 copy numbers was calculated to determine the physical status of HPV-16 viral gene. Results : We observed a significant difference in HPV prevalence between tonsillar cancer group and control group(73.1% vs. 11.6%), and most of the HPVs were type 16(87.2%) and integrated(94.1%) state. In terms of oral tongue cancer, we demonstrate that 30.5% has integrated HPV-16 in cancer tissue. But Glottic cancer only 1% is related to HPV-16 integration. Conclusion : This study revealed significant relationship of HPV prevalence with oropharyngeal and oral tongue squamous cell carcinoma. Most of HPV were 16 type and integrated or mixed, HPV-16 integration could be directly related to the carcinogenesis.