• Journal of Food Hygiene and Safety
• /
• v.34 no.3
• /
• pp.290-295
• /
• 2019

Salmonella spp. are frequently associated with food and are among the most important foodborne pathogens. The recent Salmonella out breaks in Korea was associated with chocolate mousse cakes served with school meals during September 2018. The objective of this research was to compare the 3M Molecular Detection Assay 2 - Salmonella and the Korean Standard Method of Salmonella in artificially inoculated mousse (chocolate and cheese) and tiramisu cakes. Mousse (chocolate and cheese) and tiramisu cakes were artificially inoculated with S. Typhimurium. Twenty five gram of sample was enriched with 225 mL buffered peptone water for incubation at $37^{\circ}C$ for 24 h. After enrichment, the cultures were analyzed by using the 3M Molecular Detection Assay 2 - Salmonella and the Korean Standard Method. Most of the inoculated samples showed similar results except the chocolate mousse cakes, in which real-time PCR was unable to detect S. Typhimurium even after $10^4CFU/25g$ of inoculation. However, S. Typhimurium inoculated at a concentration of $10^0CFU/25g$ was detected by using 3M Molecular Detection Assay 2 - Salmonella. In chocolate mousse, detection of S. Typhimurium using real-time PCR was partially successful when dark chocolate was added at less than 15%. Negative results in real-time PCR and 3M Molecular Detection Assay 2 - Salmonella were confirmed by gel electrophoresis. The data indicated that dark chocolate could inhibit amplification of the target gene in the PCR reactions. In conclusion, the 3M Molecular Detection Assay 2 - Salmonella was better than the Korean Standard Method (real-time PCR) for the detection of S. Typhimurium in chocolate mousse cakes and chocolate mousse.

• BMB Reports
• /
• v.31 no.1
• /
• pp.101-105
• /
• 1998

Immunoassay of botulinum toxin (BTX) B type was investigated using two typed of biosensors: light addressable potentiometric sensor (LAPS) and surface plasmon resonance (SPR) sensor. Urease-tagged and immuno-filtration capture method have been used for LAPS. Tag-free and direct binding real-time detection method have been used for SPR sensor. The detection limit of sandwich assay format with LAPS was 10 ng/ml, which was the lowest among methods tested. SPR has the advantage of being more convenient because tag-free direct binding assay can be used and reaction time was reduced, regardless of low sensitivity. This result shows that sandwich assay format with LAPS can be used as an alternative method of BTX mouse bioassay which is known as the most sensitive method for the detection of BTX.

• Journal of Oriental Neuropsychiatry
• /
• v.17 no.2
• /
• pp.37-59
• /
• 2006

Objective : This study was designed to asses the effect of Hwangryunhaedoktang and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation. Mouse neuroblastoma 2a (N2a) cells were treated by Hwangryunhaedoktang and herbs. Result : 1. Hwangryunhaedoktang was effective on LDH assay of hypoxia and reoxygenation. 2. All of herbs were generally effective on LDH assay of hypoxia and reoxygenation. In LDH assay of hypoxia, the effects of herbs depended on concentration. In MTT assay of hypoxia, Coptidis Rhizoma and Gardeniae Fructus were effective. In MTT assay of reoxygenation most of herbs were not effective. But Phellodendri Cortex was effective in high concentration. Conclusion : The results imply that Hwangryunhaedoktang and all herbs of it nay have protective effect on dementia and aging.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.10
• /
• pp.1463-1470
• /
• 2010

E. coli has long been widely used as a host system for the manufacture of recombinant proteins intended for human therapeutic use. When considering the impurities to be eliminated during the downstream process, residual host cell DNA is a major safety concern. The presence of residual E. coli host cell DNA in the final products is typically determined using a conventional slot blot hybridization assay or total DNA Threshold assay. However, both the former and latter methods are time consuming, expensive, and relatively insensitive. This study thus attempted to develop a more sensitive real-time PCR assay for the specific detection of residual E. coli DNA. This novel method was then compared with the slot blot hybridization assay and total DNA Threshold assay in order to determine its effectiveness and overall capabilities. The novel approach involved the selection of a specific primer pair for amplification of the E. coli 16S rRNA gene in an effort to improve sensitivity, whereas the E. coli host cell DNA quantification took place through the use of SYBR Green I. The detection limit of the real-time PCR assay, under these optimized conditions, was calculated to be 0.042 pg genomic DNA, which was much higher than those of both the slot blot hybridization assay and total DNA Threshold assay, where the detection limits were 2.42 and 3.73 pg genomic DNA, respectively. Hence, the real-time PCR assay can be said to be more reproducible, more accurate, and more precise than either the slot blot hybridization assay or total DNA Threshold assay. The real-time PCR assay may thus be a promising new tool for the quantitative detection and clearance validation of residual E. coli host cell DNA during the manufacturingprocess for recombinant therapeutics.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.5
• /
• pp.685-689
• /
• 2000

Due to the uncultivable nature of Mycobacterium leprae in vitro, the fast, easy, and accurate measurement of the antimicrobial drug susceptibility of this microbe has been difficult. Conventional methods for such testing are subjective, cumbersome, and expensive in some cases. Here, the utility of a reverse transcriptase-PCR (RT-PCR)-based assay for testing was examined and compared with a Buddmeyer-type radiorespirometric assay. The susceptibility of M. leprae to rifampin was determined by probing the presence of M.leprae-specific 18 kDa gene mRNA in M. leprae-infected IC-21 macrophage cells after drug treatment. The results showed that, as the refampin concentration was increased, the 360-bp cDNA products generated by the RT-PCR-based assay decreased in a dose-dependent manner as in the drug susceptibility observed in the Buddmeyer-type assay. The drug susceptibility testing of M. leprae by the RT-PCR based assay was found to be not only faster but also nearly $10^4$-fold more sensitive than the Buddmeyer-type assay. Moreover, it was also found that, unlike the RT-PCR based assay, the same testing by a DNA-PCR resulted in no differences in the 360-bp signal, regardless of the rifampin concentrations used. Accordingly, these results demonstrated that the drug susceptibility of M. leprae can be determined effectively by an RT-PCR-based assay, thereby providing a new, fast, and sensitive testing method.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.28 no.3
• /
• pp.41-62
• /
• 2002

Various kind of whitening agents have been reported in Korea, but standard efficacy protocols are not established yet. So more economical, reproducible standard efficacy assay for whitening agents are needed. As a dermatology specialist, non radio-labeled intracellular melanin assay may be a good candidate for melanogenesis assay and MTT assay with normal human melanocytes may be a good candidate for cell proliferation assay.

• Journal of Pharmaceutical Investigation
• /
• v.33 no.4
• /
• pp.273-279
• /
• 2003

Pancreatin is a enzyme mixture breaking down carbohydrates, proteins and lipids. Most pancreatin used in Korea is imported from foreign countries. However, guideline of each country for pancreatin produced from each country is different. Therefore, guideline for pancreatin imported from several countries, such as Europe, Japan and America, it is standardized to control its quality. Assay of enzyme activity for pancreatin in KP is similar to tat in JP, but it is significantly different from those in FP ad in USP. We measured pancreatin digestive activities of 17 commercial products. Activity assay of digestive enzymes, starch- and lipid-digestive enzymes, for pancreatin by KP method (including JP) was difficult compared to those by FIP ad USP methods. Particularly, activity assays of starch- and lipid-digestive enzymes by KP method were mistakable, ad varied in diluted samples than those by FIP. However, activity assay of protein-digestive enzyme by KP method was similar to that by FIP. Starch-digestive enzyme activities of 17 commercial pancreatins by KP method were lower 0.079-fold compared to those by FIP method. Their protein-digestive enzyme activities by KP method were higher 75.7-fold than those by FIP method. Their lipid-digestive enzyme activities by KP method were lower 0.234-fold compared to those by FIP method.

• CELLMED
• /
• v.10 no.4
• /
• pp.27.1-27.6
• /
• 2020

Cancer is one of the leading cause of mortality in India as well as worldwide. The management of cancer by conventional therapy has shown life threatening adverse effects. The researchers are now exploring the natural way of treatment. Unani system of medicine have rich literature for cancer and many compound formulations have been described in this system. Unani system of medicine is based on holistic approach and treat human being as a unit with natural herbs, mineral and animal origin drugs. An important compound Unani formulation (CUF) from the literature has been chosen to explore the Unani claim of its anticancer activity. The phytochemical constituents were assessed using standard phytochemical screening method. Antioxidant property of this formulation was assessed by DPPH assay. The DPPH free radical scavenging assay was carried out by colorimetric method and ascorbic acid was taken as a positive control. Three different extracts of CUF on different concentrations were used to screening on human breast cancer (BCC) MCF-7 cell line. For the estimation of in-vitro cytotoxic potency of the investigated extracts was assessed on MTT assay by using trypan blue method and paclitaxel was used as the standard. Hydro-ethanolic (HE) extract showed highest free radical scavenging activity among all extracts. DPPH Assay showed substantial antioxidant activity of these extracts in hydro-ethanol extract at 1㎍ concentration of CUF. The CUF showed antioxidant and anticancer activity. The claim made by Unani physician has been proved.

• Osong Public Health and Research Perspectives
• /
• v.5 no.4
• /
• pp.187-192
• /
• 2014

Objectives: Measurement of the incidence of the human immunodeficiency virus (HIV) is very important for epidemiological studies. Here, we determined the recency period with the AxSYM avidity assay and the BED-capture enzyme immunoassay (BED-CEIA) in Korean seroconverters. Methods: Two hundred longitudinal specimens from 81 seroconverters with incident HIV infections that had been collected at the Korea National Institute of Health were subjected to the AxSYM avidity assay (cutoff = 0.8) and BED-CEIA (cutoff = 0.8). The statistical method used to estimate the recency period in recent HIV infections was nonparametric survival analyses. Sensitivity and specificity were calculated for 10-day increments from 120 days to 230 days to determine the recency period. Results: The mean recency period of the avidity assay and BED-CEIA using a survival method was 158 days [95% confidence interval (CI), 135-181 days] and 189 days (95% CI, 170-208 days), respectively. Based on the use of sensitivity and specificity, the mean recency period for the avidity assay and BED-CEIA was 150 days and 200 days, respectively. Conclusion: We determined the recency period to estimate HIV incidence in Korea. These data showed that the nonparametric survival analysis often led to shorter recency periods than analysis of sensitivity and specificity as a new method. These findings suggest that more data from seroconverters and other methodologies are needed to determine the recency period for estimating HIV incidence.

• Journal of Oriental Neuropsychiatry
• /
• v.16 no.1
• /
• pp.19-41
• /
• 2005

Object : This study was designed to asses the effect of Sunghyangjungkisan-ga-pogongng and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation, Mouse neuroblastoma 2a (N2a) cells were treated by SHJG+P and herbs. Result : 1. SHJG+P was effective on LDH assay of hypoxia and reoxygenation. 2. The herbs were generally effective on LDH assay of hypoxia and reoxygenation. In MTT assay of hypoxia JP and GC were effecctive. In LDH assay of hypoxia all of herbs were effective. DMH, BC, SY, NS were more effective than other herbs. In LDH assay of reoxygenation KH, BH, BBR, DMH were especially effective. In MTT assay of reoxygenation most of herbs were not effective. But GC, SY, BH, JP were effective. Conclusion : The results imply that SHJG+P and all of berbs may have protective effect on dementia and GC, SY, BH, JP may have protective effect.