• 대한방사성의약품학회지
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• 제6권1호
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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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• 제28권5호
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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.

• 한국수정란이식학회지
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• 제24권2호
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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.

• 한국식품과학회지
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• 제22권5호
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• pp.596-601
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• 1990

미강의 산소 농도를 제한하고 상대습도 65% 온도 $35^{\circ}C$의 저장 조건하에서 함유 지방질의 가수분해를 최대한 유도한 시료와 온도 $25-30^{\circ}C$, 상대습도 70-80%인 공기중에 방치하여 함유 지방질의 가수분해와 지방질의 산화를 동시에 유도한 미강을 시료로 하여 지방의 산화양상에 따른 단백질의 물리 화학적인 변화 즉, sulfhydryl과 disulfide group, 단백질의 용해도, 유효성 lysine, protease의 활성변화 등을 실험하였다. 산소 농도를 제한한 system에서는 지방질의 가수분해는 급격히 일어난 반면 산화는 서서히 진행되었고, 공기 중에 방치한 system에서는 지방질의 가수분해와 자동산화가 현저하게 진행되었다. 이때 각종 단백질 기능기의 함량의 감소현상은 저장기간보다 지방의 산패 정도와 더 깊은 상관성을 보였다. 지방질의 산패와 주요 단백질 기능기함량과의 상관계수는 두 system 모두에서 -0.8 이상으로서, 지방질의 산패는 단백질의 이화학적인 변화에 중요한 영향을 미침이 관찰되었다(p<0.05).

• 한국환경성돌연변이발암원학회지
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• 제22권1호
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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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• 제22권6호
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• pp.393-400
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• 2007

현재 많은 대학과 기업에서 다양한 방법으로 상용화가 가능한 protein microarray의 개발을 위해 많은 연구를 집중하고 있다. Protein microarray의 제작 및 분석 조건을 최적화하기 위한 연구도 진행되고 있지만 protein microarray로 부터 얻은 분석 결과를 모든 연구자들이 공유하고 통합하기 위한 노력이 절실한 실정이다. 뿐만 아니라, PCR 같은 무한 확장 방법이 존재하지 않는 단백질의 특성을 고려할 때, 좀 더 실용적인 protein microarray를 많이 만들기 위해서는 수많은 단백질들과 결합할 수 있는 특이성이 높고 결합력이 강한 capture molecule들을 개발하는 것이 필수이다. 그러나 이러한 장애에도 불구하고 protein microarray는 아주 적은 시료량으로 high-throughput assay가 가능하다는 장점 때문에 현재의 생명과학의 발전 추세로 볼 때 앞으로 protein microarray가 조만간 실용화될 것이며 이의 시장성은 매우 클 것으로 기대된다. 보다 빠른 실용화를 위해서는 protein microarray의 개발에 필요한 기반 기술의 개발과 동시에 이를 활용하기 위한 contents의 개발도 절실히 요구된다.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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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.

• 한국작물학회지
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• 제55권2호
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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.

• 유기물자원화
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• 제29권2호
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• pp.25-30
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• 2021

본 연구는 인산염 인 농도 측정과 관련하여 숙련도에 의해서 정도관리의 지표가 어떻게 개선되는지를 조사하였다. 아울러 분석기기의 종류에 따른 측정값의 차이가 있는지 함께 비교하였다. 분석자의 숙련도가 분석결과에 미치는 영향을 알아보기 위해 3인의 실험자가 2종의 분석기기를 사용하여 수질오염공정시험기준에 따라 인산염 인을 7회에 걸쳐서 방법검출한계와 정량한계를 측정하였으며, 실험결과 5회 이상 반복실험하면 정도관리지표를 만족하였다. 인산염 인의 정량한계는 0.02 mg/L로 계산되었으며, 분석기기가 다른 경우 정량한계 부근의 시료에 대한 흡광도와 농도가 통계적으로 유의미하게 차이가 있음을 확인하였다.

• 한국환경농학회지
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• 제42권3호
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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.