• 한국유가공학회:학술대회논문집
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• 2002.04a
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• pp.37-42
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• 2002

Lactoferrin is an iron-binding glycoprotein and its bacteriostatic and bactericidal effects on Gram-positive and Gram-negative bacteria have been well-known. However, certain kind of lactic acid bacteria are resistant against its antibacterial effects. Moreover, it is reported that lactoferrin promotes the growth of bifidobacteria by in vitro and in vivo experiments. In this experiment, lactoferrin-binding protein was found both in the membrane and cytosolic franctions of Bifidobacterium. Bifidobacterium was grown in anaerobic conditions in MRS broth containing cysteine, gathered by centrifugation and processed by sonication. The lactoferrin-binding proteins on the PVDF-membrane transferred after SDS-PAGE were detected by far-western method using biotinylated lactoferrin and streptavidin-labeled horse radish peroxidase. Observation in growth effects of lactoferrin on Bifidobacterium suggested that there is a relation between the presence of lactoferrin-binding proteins on the cells and their growth.

• Korean Journal of Veterinary Pathology
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• v.3 no.1
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• pp.1-5
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• 1999

This experiment was carried out to establish the immunohistochemical diagnostic method for infectious pancreatic necrosis in the monolayers of CHSE-214 cell cultures and paraffin-embedded tissue sections from rainbow trout infected with infectious pancreatic necrosis virus(IPNV). Specific identification of IPNV antigens was often demonstrated in the pancreatic exocrine cells, and less in the intestinal mucous epithelia and the renal hemopoietic tissues by the use of monoclonal antibodies against capsid protein VP2. The specific reaction was seen as a distinct red cytoplasmic color, often as small granules of various sizes. The result showed that streptavidin alkaline phosphatase immunohistochemisry specifically identified IPNV antigens in both infected cell cultures and tissue sections.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1727-1732
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• 2008

We present a facile, yet versatile carbon nanofabrication method using electron beam lithography and resist pyrolysis. Various resist nanopatterns were fabricated using a negative electron beam resist, SAL-601, and were then subjected to heat treatment in an inert atmosphere to obtain carbon nanopatterns. Suspended carbon nanostructures were fabricated by wet-etching of an underlying sacrificial oxide layer. Free-standing carbon nanostructures, which contain 122 nm-wide, 15 nm-thick, and 2 ${\mu}m$-long nanobridges, were fabricated by resist pyrolysis and nanomachining processes. Electron beam exposure dose effects on resist thickness and pattern widening were studied. The thickness of the carbon nanostructures was thinned down by etching with oxygen plasma. An electrical biosensor utilizing carbon nanostructures as a conducting channel was studied. Conductance modulations of the carbon device due to streptavidin-biotin binding and pH variations were observed.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.311-317
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• 1999

Pathogenic effects of 29 different porcine reproductive and respiratory syndrome(PRRS) virus isolates were investigated in swine tracheal ring(STR) cultures by examining their effects on the ciliary activity of STR. Inhibition of ciliary movement and destruction of the tracheal epithelium were seen between 72 and 96 hours postinoculation(PI). Virus replication was demonstrated by examining viral infectivity of the supernatants from the STR cultures. PRRS virus antigen in macrophages was detected by a streptavidin-biotin complex(ABC) immunoperoxidase method. Of the 29 PRRS virus isolates, 8 isolates were classified into pathogenic, and the remaining 21 isolates were determined as mildly pathogenic or apathogenic viruses. These results suggest that STR examination may be used as a method for predicting pathogenic variability of PRRS virus isolates.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.55.1-55.1
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• 2012

In the first part of this talk, I will introduce an effort to use gold nanoparticles and UO22+ (uranyl) specific DNAzyme for development of highly sensitive and selective colorimetric uranyl sensors. In addition, I will discuss how DNA aptamers can be delivered by nanoparticles to cancer cell nucleus and released by ultrafast femtosecond pulsed laser for targeted cancer therapy. Finally, I will show how proteins such as streptavidin and myoglobin, or nanoparticles can be precisely aligned on DNA with nanometer resolution via backbone-modified phosphorothioate DNA and bifunctional linkers. These interesting functional and structural properties of DNA can provide new opportunities to develop dynamic DNA structures for potential use as intracellular sensors and drug delivery agents.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.149-154
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• 1988

Japanese Encephalitis Virus(JEV) can be detected conveniently by the use of biotinylated cDNA probe. To prepare biotinylated probe aminoallyl dUTP was first synthesized chemically to reverse transcribe the virial RNA. The allylamine-labeled cDNA was then converted to the biotin-cDNA by the reaction with an activated biotin ester, NHS-ACA-biotin. The JEV genomic RNA was hybridized to the biotinylated cDNA probe on nitrocellulose filter and visualized colorimetrically by streptavidin complexes with alkaline phosphatase polymer. Sensitivity of the detection system was determined by estimating the amount of the JEV genomic RNA through comparison with signals generated from the biotinylated and $^{32/P}$ -labeled probes. It was found that the biotin probe was as sensitive as $^{32/P}$ -cDNA probe which can detect 50pgs of the target RNA.

• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.107-113
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• 2011

LSPR(Localized Surface Plasmon Resonance) sensor measures the refractive index change on the sensor surface. The detection of biological reaction with the unknown refractive index needs to be converted into the signal sensitivity for the refractive index change for comparison with other measurements. To find the signal sensitivity, the three steps of signal processing are proposed, which are signal modeling, signal calibration and signal normalization of LSPR sensor. The detected signal of biotin-streptavidin interaction has been converted into unit of [RU](Resonance Unit) using the proposed method. The converted signal directly can be compared with the other sensors including commercialized one.

• Food Engineering Progress
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• v.14 no.1
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• pp.21-26
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• 2010

C-Reactive protein (CRP), which is an 118 kDa pentameric protein, was secreted by the liver is an important biomarker for coronary disease, hypertension and inflammation. In this study, a method for CRP detection exploiting quantum dot (Qdot)-antibody conjugate was developed according to an indirect-competitive immunosensing protocol. For this purpose, a streptavidin-bound $Qdot_{605}$ was linked with a separately prepared biotinylated monoclonal antirat CRP antibody to produce a Qdot-antibody conjugate. The immunosensing was performed at 0.1 and 20 nM of the coating antigen and conjugate, respectively. The current method was found very sensitive in CRP detection, judging from the concentration-dependent fluorescence emission.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.101-101
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• 2006

We have studied the micellisation of poly(n-butyl acrylate)-block-poly(acrylic acid) and poly(n-butyl acrylate)-graft-poly(acrylic acid) in aqueous solution. The size and structure of the formed micelles was elucidated by scattering and imaging techniques. The micelle structure depends on pH, composition, and topology: graft copolymers form much smaller micelles that block copolymers of similar composition. We have also synthesized block copolymers of acrylic acid and N-isopropylacrylamide (NIPAAm) or N,N-diethylacrylamide (DEAAm). Due to the LCST of polyNIPAAm and polyDEAAm, these block copolymers spontaneously form micelles upon heating and they form inverse micelles upon decreasing pH below 4. If the LCST block is much longer than the PAA one, this presents a very convenient way to prepare crew-cut micelles. The polymers have been successfully used as stabilizers in emulsion polymerization. They also have been conjugated to streptavidin. The conjugates reversibly form mesoscopic particles on heating.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.532-539
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• 2004

Purpose: There has been a renewal of interest in Macrophage migration inhibitory factor (MIF), especially correlation in pathogenesis of sepsis by many infectious diseases and in regulation of host inflammatory and immune response. We developed immunoradiometric assay (IRMA) to determine serum human MIF concentration. Materials and Methods: The IRMA system utilizes solid phase bound monoclonal anti-recombinant human MIF (rhMIF) antibody as a capture antibody, biotinylated polyclonal anti-rhMIF antibody as a detector antibody. We applied with rhMIF that concentration of standard solutions increased from 0 ng/ml to 100 ng/ml. We used $^{125}I$-streptavidin (SA) as radiotracer to determination of rhMIF concentration. Streptavidin was labeled with $^{125}I$ by Chloramine-T method and $^{125}I$-SA was purified by ultracentrifugation. $^{125}I$-SA stability was evaluated by ITLC analysis at $4^{\circ}C$ and room temperatures until 60days. To validate IRMA system for MIF, we experimented intra-assay and inter-assay coefficients of variation, recovery test and dilution test. Results: Radiolabeling yield of $^{125}I$-SA was 87% and purified $^{125}I$-SA retained above 99% radiochemical purity. $^{125}I$-SA showed above 93% stability in $4^{\circ}C$ until 60days that it is good for immunoradiometric assay as radiotracer. Plotted standard dose response curve showed that increased concentration of rhMIF linearly correlated (R2=0.99) with bound radioactivity of $^{125}I$-SA. The highest intra- and inter-assay coefficients of variation were 5.5% and 7.6%, respectively. The average of recovery of MIF in samples was 102%. In dilution test, linear response curves were obtained (R2=0.97). Conclusion: Radioimmunoassay using $^{125}I$-SA as radiotracer thought to be useful for the determination of serum MIF concentration, and further, its data will be used to evaluate the correlation between clinical significance and serum MIF concentration in patients with various inflammatory diseases.