http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
3D Droplet Microfluidic Systems for High-Throughput Biological Experimentation
Kang, Dong-Ku,Gong, Xiuqing,Cho, Soongwon,Kim, Jin-young,Edel, Joshua B.,Chang, Soo-Ik,Choo, Jaebum,deMello, Andrew J. American Chemical Society 2015 ANALYTICAL CHEMISTRY - Vol.87 No.21
<P>Herein, we describe the development of a multilayer droplet microfluidic system for creating concentration gradients and generating microdroplets of varying composition for high-throughput biochemical and cell-based screening applications. The 3D droplet-based microfluidic device consists of multiple PDMS layers, which are used to generate logarithmic concentration gradient reagent profiles. Parallel flow focusing structures are used to form picoliter-sized droplets of defined volumes but of varying composition. As proof of concept, we demonstrate rapid enzymatic activity assays and drug cytotoxicity assays on bacteria. The 3D droplet-based microfluidic platform has the potential to allow for high-efficiency and high-throughput analysis, overcoming the structural limitations of single layer microfluidic systems.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2015/ancham.2015.87.issue-21/acs.analchem.5b02402/production/images/medium/ac-2015-02402t_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac5b02402'>ACS Electronic Supporting Info</A></P>
Cho, Soongwon,Kang, Dong-Ku,Sim, Steven,Geier, Florian,Kim, Jin-Young,Niu, Xize,Edel, Joshua B.,Chang, Soo-Ik,Wootton, Robert C. R.,Elvira, Katherine S.,deMello, Andrew J. American Chemical Society 2013 ANALYTICAL CHEMISTRY - Vol.85 No.18
<P>We present a fully integrated droplet-based microfluidic platform for the high-throughput assessment of photodynamic therapy photosensitizer (PDT) efficacy on <I>Escherichia coli</I>. The described platform is able to controllably encapsulate cells and photosensitizer within pL-volume droplets, incubate the droplets over the course of several days, add predetermined concentrations of viability assay agents, expose droplets to varying doses of electromagnetic radiation, and detect both live and dead cells online to score cell viability. The viability of cells after encapsulation and incubation is assessed in a direct fashion, and the viability scoring method is compared to model live/dead systems for calibration. Final results are validated against conventional colony forming unit assays. In addition, we show that the platform can be used to perform concurrent measurements of light and dark toxicity of the PDT agents and that the platform allows simultaneous measurement of experimental parameters that include dark toxicity, photosensitizer concentration, light dose, and oxygenation levels for the development and testing of PDT agents.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2013/ancham.2013.85.issue-18/ac4022067/production/images/medium/ac-2013-022067_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac4022067'>ACS Electronic Supporting Info</A></P>
( Soong Won Cho ),( Dong Ku Kang ),( Jae Bum Choo ),( Andrew J. Demello ),( Soo Ik Chang ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.11
Advances in the fields of proteomics and genomics have necessitated the development of high-throughput screening methods (HTS) for the systematic transformation of large amounts of biological/ chemical data into an organized database of knowledge. Microfluidic systems are ideally suited for high-throughput biochemical experimentation since they offer high analytical throughput, consume minute quantities of expensive biological reagents, exhibit superior sensitivity and functionality compared to traditional micro-array techniques and can be integrated within complex experimental work flows. A range of basic biochemical and molecular biological operations have been transferred to chip- based microfluidic formats over the last decade, including gene sequencing, emulsion PCR, immunoassays, electrophoresis, cell- based assays, expression cloning and macromolecule blotting. In this review, we highlight some of the recent advances in the application of microfluidics to biochemistry and molecular biology. [BMB reports 2011; 44(11): 705-712]
Analysis of Protein–Protein Interactions by Using Droplet-Based Microfluidics
Srisa-Art, Monpichar,Kang, Dong-Ku,Hong, Jongin,Park, Hyun,Leatherbarrow, Robin J.,Edel, Joshua B.,Chang, Soo-Ik,deMello, Andrew J. WILEY-VCH Verlag 2009 Chembiochem Vol.10 No.10
<P>Every little drop: The K<SUB>D</SUB> values of angiogenin (ANG) interactions as shown by FRET analysis of thousands of pL-sized droplets agree with data from bulk-fluorescence polarization measurements. Importantly, the use of fluorophores does not affect the activity of ANG or the binding of anti-ANG antibodies to ANG. Such an experimental platform could be applied to the high-throughput analysis of protein–protein interactions. <img src='wiley_img/14394227-2009-10-10-CBIC200800841-content.gif' alt='wiley_img/14394227-2009-10-10-CBIC200800841-content'> </P> <B>Graphic Abstract</B> <P>Every little drop: The K<SUB>D</SUB> values of angiogenin (ANG) interactions as shown by FRET analysis of thousands of pL-sized droplets agree with data from bulk-fluorescence polarization measurements. Importantly, the use of fluorophores does not affect the activity of ANG or the binding of anti-ANG antibodies to ANG. Such an experimental platform could be applied to the high-throughput analysis of protein–protein interactions. <img src='wiley_img/14394227-2009-10-10-CBIC200800841-content.gif' alt='wiley_img/14394227-2009-10-10-CBIC200800841-content'> </P>
Choi, Jae-Won,Kang, Dong-Ku,Park, Hyun,deMello, Andrew J.,Chang, Soo-Ik American ChemicalSociety 2012 ANALYTICAL CHEMISTRY - Vol.84 No.8
<P>Droplet-based microfluidic systems have emerged as a powerful platform for performing high-throughput biological experimentation. In addition, fluorescence polarization has been shown to be effective in reporting a diversity of bimolecular events such as protein-protein, DNA-protein, DNA-DNA, receptor-ligand, enzyme-substrate, and protein-drug interactions. Herein, we report the use of fluorescence polarization for high-throughput protein-protein interaction analysis in a droplet-based microfluidic system. To demonstrate the efficacy of the approach, we investigate the interaction between angiogenin (ANG) and antiangiogenin antibody (anti-ANG Ab) and demonstrate the efficient extraction of dissociation constants (K-D = 10.4 +/- 3.3 nM) within short time periods.</P>
Lee Jee Hyung,Kim Haeryoung,이상협,Ku Ja-Lok,Chun Jung Won,Seo Ha Young,Kim Soon Chan,Paik Woo Hyun,Ryu Ji Kon,Lee Sang Kook,Lowy Andrew M.,Kim Yong-Tae 거트앤리버 소화기연관학회협의회 2022 Gut and Liver Vol.16 No.4
Background/Aims: Three-dimensional cultures of human pancreatic cancer tissue also known as “organoids” have largely been developed from surgical specimens. Given that most patients present with locally advanced and/or metastatic disease, such organoids are not representative of the majority of patients. Therefore, we used endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) to collect pancreatic cancer tissues from patients with advanced pancreatic cancer to create organoids, and evaluated their utility in pancreatic cancer research. Methods: Single-pass EUS-FNA samplings were employed to obtain the tissue for organoid generation. After establishment of the organoid, we compared the core biopsy tissues with organoids using hematoxylin and eosin staining, and performed whole exome sequencing (WES) to detect mutational variants. Furthermore, we compared patient outcome with the organoid drug response to determine the potential utility of the clinical application of such organoid-based assays. Results: Organoids were successfully generated in 14 of 20 tumors (70%) and were able to be passaged greater than 5 times in 12 of 20 tumors (60%). Among them, we selected eight pairs of organoid and core biopsy tissues for detailed analyses. They showed similar patterns in hematoxylin and eosin staining. WES revealed mutations in KRAS, TP53, CDKN2A, SMAD4, BRCA1, and BRCA2 which were 93% homologous, and the mean nonreference discordance rate was 5.47%. We observed moderate drug response correlations between the organoids and clinical outcomes in patients who underwent FOLFIRINOX chemotherapy. Conclusions: The established organoids from EUS-FNA core biopsies can be used for a suitable model system for pancreatic cancer research.
Laurent, Louise C.,Ulitsky, Igor,Slavin, Ileana,Tran, Ha,Schork, Andrew,Morey, Robert,Lynch, Candace,Harness, Julie V.,Lee, Sunray,Barrero, Maria J.,Ku, Sherman,Martynova, Marina,Semechkin, Ruslan,Gal Elsevier 2011 Cell stem cell Vol.8 No.1
<P><B>Summary</B></P><P>Genomic stability is critical for the clinical use of human embryonic and induced pluripotent stem cells. We performed high-resolution SNP (single-nucleotide polymorphism) analysis on 186 pluripotent and 119 nonpluripotent samples. We report a higher frequency of subchromosomal copy number variations in pluripotent samples compared to nonpluripotent samples, with variations enriched in specific genomic regions. The distribution of these variations differed between hESCs and hiPSCs, characterized by large numbers of duplications found in a few hESC samples and moderate numbers of deletions distributed across many hiPSC samples. For hiPSCs, the reprogramming process was associated with deletions of tumor-suppressor genes, whereas time in culture was associated with duplications of oncogenic genes. We also observed duplications that arose during a differentiation protocol. Our results illustrate the dynamic nature of genomic abnormalities in pluripotent stem cells and the need for frequent genomic monitoring to assure phenotypic stability and clinical safety.</P> <P><B>Highlights</B></P><P>► hESCs and hiPSCs show more gene copy number variation than somatic cells ► Degree of abnormality differs more between hESC lines than hiPSC lines ► Deletions common in hiPSCs after reprogramming, duplications appear over time ► Recurrent duplications occur at specific genomic loci in pluripotent cells</P>