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Lee M.,Chonbuk National University | Cho K.,Logos Biosystems Inc. | Yoon D.,South Korean National Institute of Animal Science | Yoo D.J.,Seonam University | Kang S.H.,Chonbuk National University
Electrophoresis | Year: 2010

A portable CE system was developed for the identification of cattle breeds. The system had a width of 44 cm, depth of 27 cm, height of 13 cm, and a weight of only ∼8 kg and included an LIF detector, with everything integrated into a small box. The specific sizes of genes were quickly separated and detected with a high sensitivity based on the difference in the DNA mobility using a diode-pumped solid-state LIF detector. Using this system, the 100-bp DNA ladder was analyzed under a 1.0% PVP (M r = 300 000) sieving gel matrix in a fused silica capillary with LODs of 4.4-13.0 pg/mL (S/N = 3) for 100-3000 bp DNAs, which indicates ten times improved value than other commercialized portable CE system. The migration times and the peak areas showed good reproducibilities with relative standard deviations that were less than 0.49 and 1.3% (n = 5), respectively. Based on the difference in the DNA mobility of the microsatellite and SNP markers, Korean cattle and Holstein were exactly identified as the model cattle breeds within 32 and 3.5 min, respectively. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Park J.,Soongsil University | Park J.-H.,Soongsil University | Ock K.-S.,Soongsil University | Ganbold E.-O.,Soongsil University | And 4 more authors.
Journal of Colloid and Interface Science | Year: 2011

Intracellular uptake of serum-coated gold nanoparticles (AuNPs) in a single mammalian cell was examined in order to investigate the interactions of cell culture media and aromatic thiol-functionalized gold surfaces using micro-spectroscopic tools. The AuNPs modified by the aromatic thiols of para-aminobenzenethiol (ABT), para-hydroxy benzenethiol (HBT), and para-carboxylic benzenethiol (CBT, para-mercaptobenzoic acid) bearing NH 2, OH, and COOH surface functional groups are presumed to adsorb the serum proteins as indicated from the compiled quartz crystal microbalance (QCM) data. The QCM results indicate that among the constituents, fetal bovine serum (FBS) should be the major adsorbate species on AuNPs incubated in Roswell Park Memorial Institute (RPMI) medium. The functionalized AuNPs were found to be internalized as an aggregation state in mammalian cells as evidenced by transmission electron microscopy (TEM) images. We monitored such cellular uptake behaviors of aromatic thiol-modified AuNPs using dark-field microscopy (DFM)-guided confocal surface-enhanced Raman scattering techniques in order to identify the three-dimensional localization inside the single cell. We found that the uptake amounts of ABT, HBT, and CBT were similar by counting up to 70 particles inside the cells incubated in the solution mixture of the aromatic thiol and 1,4-phenylenediisocyanide (PDIC) as a reference. This result indicates for the short aromatic thiol compounds, the AuNPs should enter the cell after the serum-coating regardless of the surface functional groups. Considering that the aromatic thiols have little effect on the serum coating, the DFM/SERS method is an effective tool for monitoring the localization of AuNPs inside a single cell. © 2011 Elsevier Inc.

Seo J.H.,Soongsil University | Cho K.,Logos Biosystems Inc. | Lee S.Y.,Seoul National University | Joo S.-W.,Soongsil University
Nanotechnology | Year: 2011

Using live-cell imaging techniques we investigated concentration-dependent intracellular movements of fluorescence nanoparticles (NPs) in real-time after their entry into HeLa cells via incubation. Intracellular particle traces appeared to be a mixture of both random and fairly unidirectional movements of the particles. At rather low concentrations of NPs, a majority of the non-random intracellular particle trajectories are assumed to mostly go along microtubule networks after endocytosis, as evidenced from the inhibition test with nocodazole. On the other hand, as the concentrations of NPs increased, random motions were more frequently observed inside the cells. © 2011 IOP Publishing Ltd.

Kim M.,Soongsil University | Seo J.H.,Soongsil University | Jeon W.I.,Seoul National University | Kim M.-Y.,Soongsil University | And 3 more authors.
Talanta | Year: 2012

The anticancer drug doxorubicin (DOX) appeared to adsorb efficiently on TiO 2 nanoparticles (NPs) as evidenced by visible absorption and diffuse reflectance infrared spectroscopy data. The adsorbed drugs were found released in a controlled way by external glutathione (GSH). Fluorescence of DOX appeared to be quenched substantially by TiO 2 NPs. The fabrication and release of DOX on TiO 2 NPs were checked by monitoring the fluorescence. We could monitor real-time drug release in the live cell using fluorescence imaging techniques. By these methods, we were able to monitor up to a nanomolar amount of DOX release in vitro from TiO 2 NPs triggered by external GSH. In vivo fluorescence images of DOX were obtained from the subcutaneous site in living mice after GSH treatment. On the basis of label-free fluorescence quenching measurements, a real-time release of DOX on TiO 2 NPs can be monitored in vitro and in vivo after an external trigger of GSH. © 2011 Elsevier B.V. All rights reserved.

Park J.-H.,Soongsil University | Park J.,Soongsil University | Dembereldorj U.,Soongsil University | Cho K.,Logos Biosystems Inc. | And 4 more authors.
Analytical and Bioanalytical Chemistry | Year: 2011

We investigated the cellular uptake behavior of non-fluorescent metal nanoparticles (NPs) by use of surface-enhanced Raman scattering (SERS) combined with dark-field microscopy (DFM). The uptake of Au NPs inside a single cell could also be identified by DFM first and then confirmed by z-depth-dependent SERS at micrometer resolution. Guided by DFM for the location of Au NPs, an intracellular distribution assay was possible using Raman dyes with unique vibrational marker bands in order to identify the three-dimensional location inside the single cell by obtaining specific spectral features. Au NPs modified by 4-mercaptobenzoic acid (MBA) bearing its -COOH surface functional group were used to conjugate transferrin (Tf) protein using the 1-ethyl-3-[3- dimethylaminopropyl]carbodiimide hydrochloride (EDC) reaction. The protein conjugation reaction on Au surfaces was examined by means of color change, absorption spectroscopy, and SERS. Our results demonstrate that DFM techniques combined with SERS may have great potential for monitoring biological processes with protein conjugation at the single-cell level. [Figure not available: see fulltext.] © 2011 Springer-Verlag.

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