• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.1
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• pp.20-26
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• 2020

Accelerator mass spectrometry (AMS) is a powerful detection technique with the exquisite sensitivity and high precision compared with other traditional analytical techniques. Accelerator mass spectrometry can be widely applied in the technique of radiocarbon dating in the fields of archeology, geology and oceanography. The ability of accelerator mass spectrometry to measure rare ¹⁴C concentrations in microgram and even sub-microgram amounts suggests that extension of ¹⁴C-accelerator mass spectrometry to biomedical field is a natural and attractive application of the technology. Drug development processes are costly, risky, and time consuming. However, the use of ¹⁴C-accelerator mass spectrometry allows absorption, distribution, metabolism and excretion (ADME) studies easier to understand pharmacokinetics of drug candidates. Over the last few decades, accelerator mass spectrometry and its applications to preclinical/clinical trials have significantly increased. For accelerator mass spectrometry analysis of biological samples, graphitization processes of samples are important. In this paper, we present a detailed sample preparation procedure to apply to graphitization of biological samples for accelerator mass spectrometry.

• KSBB Journal
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• v.28 no.5
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• pp.295-302
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• 2013

Indigo is utilized in various industries including textile dyeing, cosmetics, printing and medicinal products and its reduced form, leuco-indigo, is mainly used in these process. Chemical reducing agent (sodium dithionite, sodium sulfide, etc.) is preferred to use for the formation of leucoindigo in industry. In traditional indigo fermentation process, microorganisms can participate in the reduction of indigo and thus it has been known to reduce environmental pollution and noxious byproducts. However, in fermentation method using microorganisms it is difficult to standardize large scale production process due to low yield and reproducibility. In this study, we attempted to develop the indigo reduction process using microbial flora which was isolated from naturally fermented indigo vat or deduced by metagenomic approach. From the results of library analyses of PCR-amplified 16S rRNA genes from the traditional indigo fermentation vat sample (metagenome), it was confirmed that Alkalibacteriums (71%) was distinctly dominant in population. Some strains were identified after confirming that they become pure culture in nutrient media modified slightly. Four strains were separated in this process and each strain showed obvious reducing ability toward indigo in dyeing test. It is expected that the analyzed results will provide important data for standardizing the natural fermentation of indigo and investigating the mechanism of indigo reduction.

• Journal of Embryo Transfer
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• v.24 no.2
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• pp.77-87
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• 2009

To understand molecular and cellular mechanisms of many gene products in the female reproductive organs including the ovary and uterine endometrium as well as during embryo development, researchers have developed and utilized many effective methodologies to analyze gene expression in cells, tissues and animals over the last several decades. For example, blotting techniques have helped to understand molecular functions at DNA, RNA and protein levels, and the reverse transcription-polymerase chain reaction (RT-PCR) method has been widely used in gene expression analysis. However, some conventional methods are not sufficient to understand regulation and function of genes expressed in very complex patterns in many organs. Thus, it is required to adopt more high-throughput and reliable techniques. Here, we describe several techniques used widely recently to analyze gene expression, including annealing control based-PCR, differential display-PCR, expressed sequence tag, suppression subtractive hybridization and microarray techniques. Use of these techniques will help to analyze expression pattern of many genes from small scale to large scale and to compare expression patterns of genes in one sample to another. In this review, we described principles of these methodologies and summarized examples of comparative analysis of gene expression in female reproductive organs with help of those methodologies.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.596-601
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• 1990

The effects of peroxidized lipid on the protein in the biological system of rice bran was studied by determining the changes in the content of functional groups under two different storage conditions. One stored at controlled atmosphere of $35^{\circ}C$ with relative humidity 65% and the other one was exposed to the air of $25^{\circ}-30^{\circ}C$ with relative humidity 70-90%. The lipid peroxidation started after the lipolysis was almost completed. The autoxidation occurred much faster in the bran exposed to the air than that stored in the controlled atmosphere. Substantial changes in the physiochemical characteristics were observed in all of the major functional groups in both of the samples. The content of sulfhydryl and available lysine decrease·1 as lipid peroxidation progressed. Protease activity was lost almost completely. Protein solubility and in vitro digestibility also decreased during storage. The lipid peroxidation and contents of major protein functional groups were significantly correlated (p<0.05) and the correlation coefficients were higher than -0.8, for the both of the sample. peroxidized lipid was found to deteriorate protein in the biological system as well.

• Environmental Mutagens and Carcinogens
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• v.22 no.1
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• pp.47-53
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• 2002

Essential hypertension is complex disorder influenced by multiple genetic and environmental factors. Alterations of lipid metabolism in plasma have been reported to be related to an increased risk of essential hypertension. The aim of this study was to investigate the relationship between two SNPs of the human LDL receptor and CETP gene and hypertension in Korean population. There were no significant differences in allele and genotype frequencies of two SNPs in normotensives and hypertensives. With respect to Hinc II RFLP in the LDL receptor gene, pooled odds ratio value indicated the significant heterogeneity among populations studied by meta-analysis (Breslow-Day test df = 2, P<0.05). In the case of Bam HI RFLP in the CETP gene,. our study is the first report of an association between the SNP of the CETP gene and hypertension, although our result failed to demonstrate the significant association between the Bam HI RFLP of the CETP gene and hypertension in Korean population. Further work, using larger sample sizes and various ethnic groups, is required to establish the precise role of these two candidate gene polymorphisms on hypertension.

• KSBB Journal
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• v.22 no.6
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• pp.393-400
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• 2007

Analysis of protein interactions/functions in a microarray format has been of great potential in drug discovery, diagnostics, and cell biology, because it is amenable to large-scale and high-throughput biological assays in a rapid and economical way. In recent years, the protein microarray have broaden their utility towards the global analysis of protein interactions on a proteome scale, the functional activity analysis based on protein interactions and post-translational modifications (PTMs), and the discovery of biomarkers through profiling of protein expression between sample and reference pool. As a promising tool for proteomics, the protein microarray technology has advanced outstandingly over the past decade in terms of surface chemistry, acquisition of relevant proteins on a proteomic level, and detection methods. In this article, we briefly describe various techniques for development of protein microarray, and introduce developmental state of protein microarray and its applications.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.312-317
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• 2002

Indigenous lactobacilli were isolated from vaginas of Korean women for possible use in ecological treatment of bacterial vaginosis. Vaginal swab samples were obtained from a gynecological clinic and streaked on Rogosa SL agar plates to select the most predominant lactobacilli in each sample. The preliminary identification of the isolates as lactobacilli was based on microscopic observation of Gram-positive rod-shaped cell morphology. The initial characterization was performed on 108 isolates in terms of their cell surface hydrophobicity (CSH), antimicrobial activity, and hydrogen peroxide (H₂O₂) production capability, and 10 isolates were then selected for further molecular identification. For a rapid procedure to identify lactobacilli, polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses of the l6S rRNA genes were applied. The 10 selected lactobacilli and 9 different reference strains of Lactobacillus spp. were characterized by PCR-RFLP where the amplified l6S rDNA was digested with 7 different restriction endonucleases prior to analysis. DNA sequencing of the 16S rRNA gene of one particular isolate, KLB 46, that had been identified as L. crispatus by the PCR-RFLP analysis, further confirmed its identity as L. crispatus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.159-164
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• 2010

Specialty barley extracts were prepared and investigated for its antioxidant activity and biological activity. Hunter $L^*$ values of the Iksan 86 extracts had higher than that of the Iksan 87 and Zasoojeongchal extracts. The extraction yields of Iksan 86, Iksan 87, and Zasoojeongchal was 8.08, 6.62, and 7.30%, respectively. The contents of total phenolic compounds of the Iksan 86, Iksan 87, and Zasoojeongchal extracts were 16.24, 15.51, and 13.95 GAE mg/g of sample, respectively. The DPPH radical scavenging activity of Iksan 86, Iksan 87, and Zasoojeongchal extracts were 50.00, 33.27, and 7.56% at a 500 ppm, respectively. The samples showed an inhibition of xanthin oxidase. ACE inhibition effect of specialty barley extracts, Iksan 86, Iksan 87, and Zasoojeongchal, was 39.81, 41.06, and 27.78%, respectively. Tyrosinase inhibition rates (%) of Iksan 86, Iksan 87, and Zasoojeongchal extracts were 26.21, 24.57, and 20.00%, respectively. Results indicated that specialty barley extracts possesses various biological activities including antioxidative capacity, xanthin oxidase inhibition activity, angiotensin converting enzyme inhibition activity, and tyrosinase inhibition activity.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.2
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• pp.25-30
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• 2021

This study investigated how the indicators of quality control are improved by proficiency in the measurement of phosphate concentration. In addition, analysis equipments were to be compared to see if there were any differences in measurements depending on the type of analysis device. In order to find out the effect of the proficiency of the analyst on the analysis results, three analysts measured phosphate concentration seven times in accordance with the Korean water pollution test standards, and met the quality control indices if repeated more than five times. The limit of quantification for phosphate was calculated at 0.02 mg/L. If the analysis devices are different, the absorbance and concentration of the samples near the limit of quantification are statistically significant difference.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.220-230
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• 2023

Imidacloprid is a neonicotinoid insecticide widely used for insect control in a variety of crops. The evaluation of imidacloprid total residues in animal feeds derived from crop by-products is required to ensure the safety of livestock products. We performed simultaneous LC/MS/MS analyses of imidacloprid and its metabolites in five different livestock products including beef, pork, chicken, milk and egg from domestic markets. The methods for sample preparation and instrumental analysis were established by modifying QuEChERS method to meet the Codex guidelines. The methods generated 0.0035 mg/kg of the limit of determination (LOD), 0.01 mg/kg of the limit of quantitation (LOQ) and standard calibration linearity with >0.983 of the coefficients of determination (R²). The methods exhibited the recovery values of imidacloprid and its metabolites ranging from 65.66 to 119.27% without any interference between matrices. Imidacloprid total residues in the livestock products were found as values lower than the LOQ and maximum residue limits (MRLs). This study suggests that the methods are successfully applicable for the safety evaluation of imidacloprid total residues in livestock products from domestic markets.