• Korean Journal of Microbiology
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• v.51 no.3
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• pp.199-208
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• 2015

Biologics and medical devices manufactured with bovine-derived raw materials have the risk of viral contamination. Therefore, viral validation study is essential to ensure the safety of the products. Bovine adenovirus type-1 (BAdV-1) is one of the common bovine viral pathogens. For quantitative detection of BAdV-1 during the manufacture of biologics and medical devices, a TaqMan probe real-time PCR method was developed. Specific primers and TaqMan probe for amplifying and detecting BAdV-1 DNA were designed. Specificity, limit of detection (LOD), and robustness of the method was validated according to international guideline on the validation of nucleic acid amplification tests for the pathogen detection. The sensitivity of the assay was found to be $7.44{\times}10^1\;TCID_{50}/ml$. The real-time PCR method was reproducible, very specific to BAdV-1, and robust. Moreover, the method was successfully applied to the validation of Chinese Hamster Ovary (CHO)-K1 cells artificially infected with BAdV-1, a commercial CHO master bank, and bovine type 1 collagen. The overall results indicate that this rapid, specific, sensitive, and robust assay can be reliably used for quantitative detection of BAdV-1 contamination during the manufacture of biologics and medical devices using bovine-derived raw materials.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.12-19
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• 2012

Recently, the market of skin-care device has been steadily growing up. In this paper, we tried to develop a personal compound stimulus device more competitive than existing products. As the compound stimulus, biochemical stimulus of herbal extraction fluid, thermal stimulus of plate-shaped carbon fiber heater, and optical stimulus of near infrared LED were selected. By some evaluation tests, the thermal stimulation part and the optical stimulation part were found to be developed properly. Additionally, the efficacy of the mixed stimulus of thermal and optical stimulation was tested in C2C12 mouse myoblast. Through RT-PCR analysis, it was found that, by the developed compound stimulus, the expression of collagen I mRNA and collagen III mRNA increased by 4.9 and 1.3 times respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1309-1316
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• 2011

This paper presents a high-speed RNA microextractor for the direct isolation of RNA from blood lysate using magnetic oligo(dT) beads. The extraction is performed through lateral magnetophoresis, which is induced by a ferromagnetic wire array inlaid. With this RNA microextractor, more than 80% of the magnetic beads could be separated at a flow rate up to 20 ml/h, and the overall extraction procedure was completed within 1 min. The absorbance ratio of RNA to protein(A260/A280) was greater than 1.7, indicating that the extraction technique yields pure RNA. The feasibility of using this technique in reverse transcription polymerase chain reaction procedures was investigated by cDNA synthesis and PCR processes. The results confirmed that the RNA microextractor is a practical device for easy, fast, and high-precision RT-PCR using minimal amounts of reagent.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.377-382
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• 2015

The purpose of this study was to evaluate the validity and reliability of plaque scoring system using new Qraycam (All in One Bio, Korea) device which enables plaque score without tooth disclosing. This study measured Quigley-Hein index and plaque control record by both Qraycam and disclosing agent on 64 elderly people and checked degree of congruence between the two methods. Reliability was evaluated with the mean of measured values, kappa index and intraclass correlation coefficient statistical analysis. The analysis of the plaque scores showed a high agreement between the measured values according to the method of measurement and the measured part. The mean of plaque index of anterior labial were not significantly different according to measurement method. The kappa index was higher by Qraycam and tooth disclosing method of plaque index. Therefore, it was verified that Qraycam has sufficient reliability as screening tool for plaque scoring system.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1082-1086
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• 2014

A multi-channel microchip electrophoresis (MCME) method with parallel laser-induced fluorescence (LIF) detection was developed for rapid screening of H1N1 virus. The hemagglutinin (HA) and nucleocapsid protein (NP) gene of H1N1 virus were amplified using polymerase chain reaction (PCR). The amplified PCR products of the H1N1 virus DNA (HA, 116 bp and NP, 195 bp) were simultaneously detected within 25 s in three parallel channels using an expanded laser beam and a charge-coupled device camera. The parallel separations were demonstrated using a sieving gel matrix of 0.3% poly(ethylene oxide) ($M_r$ = 8,000,000) in $1{\times}$ TBE buffer (pH 8.4) with a programmed step electric field strength (PSEFS). The method was ~20 times faster than conventional slab gel electrophoresis, without any loss of resolving power or reproducibility. The proposed MCME/PSEFS assay technique provides a simple and accurate method for fast high-throughput screening of infectious virus DNA molecules under 400 bp.

• Progress in Superconductivity
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• v.12 no.1
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• pp.23-26
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• 2010

A double line commutation (DLC) type SFCL with first peak limiting function has been proposed for ideal fault current limiting operation. Very fast switching (commutation) without any arc or high voltage problems for any kind of switching device is needed for the first peak current limiting. We've tried to find suitable conditions for a successful switching of a Vacuum Interrupter (VI) with HTS elements as a Peak Current limiting Resistance (PCR).

• Journal of Sensor Science and Technology
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• v.27 no.4
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• pp.237-241
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• 2018

The real-time enrichment and detection of pathogens are serious issues and rapidly evolving field of research because of the ability of these pathogens to cause infectious diseases. In general, bacterial detection is accomplished by conventional colony counting or by polymerase chain reaction (PCR) after DNA extraction. As colony counting requires considerable time to cultivate, PCR is an attractive method for rapid detection. A small number of pathogens can cause diseases. Hence, a pretreatment process, such as enrichment is essential for detecting bacteria in an actual environment. Thus, in this study, we developed a microfluidic chip capable of performing rapid enrichment of bacteria and the extraction of their genes. A lectin, i.e., Concanavalin A (ConA), which shows binding affinity to the surface of most bacteria, was coated on the surface of magnetic particles to nonspecifically capture bacteria. It was subsequently concentrated through magnetic forces in a microfluidic channel. To lyse the captured bacteria, magnetic particles were irradiated by a wavelength of 532nm. The photo-thermal effect on the particles was sufficient for extracting DNA, which was consequently utilized for the identification of bacteria. Our device will help monitor the existence of bacteria in various environmental situations such as water, air, and soil.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.91-98
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• 2022

Tetanus is a potentially fatal public health illness resulted from the neurotoxins generated by Clostridium tetani. C. tetani is not easily culturable and culturing the relevant bacteria from infected wounds has rarely been useful in diagnosis; PCR-based assays can only be conducted at highly sophisticated laboratories. Therefore, a real-time recombinase polymerase amplification assay (Exo-RPA) was constructed to identify the fragments of the neurotoxin gene of C. tetani. Primers and the exo probe targeting the conserved region were designed, and the resulting amplicons could be detected in less than 20 min, with a detection limit of 20 copies/reaction. The RPA assay displayed good selectivity, and there were no cross-reactions with other infectious bacteria common in penetrating wounds. Tests of target-spiked serum and pus extract revealed that RPA is robust to interfering factors and has great potential for further development for biological sample analysis. This method has been confirmed to be reliable for discriminating between toxic and nontoxic C. tetani strains. The RPA assay dramatically improves the diagnostic efficacy with simplified device architecture and is a promising alternative to real-time PCR for tetanus detection.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.83-91
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• 2014

The passive UHF RFID tags for item-level tagging are now explosively used in the supply chain and retail applications as they have several advantages, the two most relevant are cost and a longer read range. However, the signal interference problem between RFID tags and smart devices in real world is expected according to the smart-phone and tablet market growth together. The performance of RFID tags can be significantly less. The popular examples are the read-success rates and read range reduction. Especially, KT Corp. recently emphasized the serious signal interference at 900 MHz of LTE and old RFID frequencies through their public demonstration. By popular demands, this paper suggests the interference tolerance measurement method between the passive UHF RFID tag and the transmitted signal from a smart device. In addition, we selected three passive UHF RFID tags(Inlay) available on the market and quantitatively evaluated read range reduction results by interference signals using the PCR(Performance Change Rates) index. As a result, the LTE system is about three times as effective as the WCDMA system in terms of interference effects, and the read range performance of two RFID tags about 60 % drop.

• Journal of Embryo Transfer
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• v.25 no.4
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• pp.259-262
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• 2010

Optimization of the preimplantation mammalian embryo culture condition was widely focused on refining medium composition under the name of chemically defined media. However, recent research revealed that the alteration of physical environment can be a crucial factor to a successful embryo development. In this study, under the same embryo density, a novel culture device named oil-free micro tube culture (MTC) system was evaluated using porcine parthenogenetic embryos. The activated oocytes were placed into the 0.2 ml thin-wall flat cap PCR tube and cultured to the blastocyst stage. As a preliminary step, embryo density and culture medium volume were optimized under a standard drop culture system. The optimal embryo density range for in vitro culture was 0.5 embryos per ${\mu}l$ in $20\;{\mu}l$ drop (20.5%) and 1.0 embryos per ${\mu}l$ in $10\;{\mu}l$ drop (20.6%). Based on these results, we compared drop culture system and 'MTC' system in terms of the developmental rate to the blastocyst stage. In $20\;{\mu}l$ medium volume, the 'MTC' system showed similar blastocyst formation rate when compared with drop culture system (20.2% versus 20.5%, respectively) while the 'MTC' system showed lower blastocyst formation rate than drop culture system in $10\;{\mu}l$ one (12.7% versus 20.0%, respectively). Therefore the $20\;{\mu}l$ MTC system may be an alternative incubation system for short-distance embryo transport without carrying the $CO_2$ incubator and this provides novel embryo culture device to clinical veterinary embryologists.