• 한국동물학회지
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• 제37권4호
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• pp.524-530
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• 1994

An Arpase complex has been purified to apparent homogeniety from the extract of chick skeletal muscle using conventional column chromatographies and glycerol density gradient centrifugation. This eWe has a sedimentation coefficient of 15S as determined by the gradient centrifugation and therefore is referred to as the 15S ATPase. It behaves as a 600-kOa molecule upon gel filtration analysis using a Superose-6 column. However, the ATPase runs as a 95-kDa polvpeptide when analyzed by polvacrvlamide gel electrophoresis in the presence of sodium dodecyl sulfate. Thus, the Arpase is likely to consist of six identical subunits of 95 KDa. It has a Km value of 0.6 mM for ATP and is maximally active at pH 9.

• 한국토양비료학회지
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• 제45권1호
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• pp.30-36
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• 2012

The active fraction of soil organic matter, which includes organic debris and light organic fraction, plays a major role in nutrient cycling. In addition, particulate organic matter is a valuable index of labile soil organic matter and can reflect differences in various soil behaviors. Since soil organic matter bound to soil mineral particles has its density lower than soil minerals, we partitioned soil organic matter into debris ($<1.5g\;cm^{-3}$), light fraction ($1.5-2.0g\;cm^{-3}$), and heavy fraction ($>2.0g\;cm^{-3}$), based on high density $ZnCl_{2-}$ sucrose solutions. Generally, partitioned organic bands were clearly separated, demonstrating that the $ZnCl_{2-}$ sucrose solutions are useful for such a density gradient centrifugation. The available gradient ranges from 1.2 to $2.0g\;cm^{-3}$. Although there was not a statistically meaningful difference in organic debris and organomineral fractions among the examined soils, there was a general trend that a higher content of organic debris resulted in a higher proportion of light organomineral fraction. In addition, high clay content was associated with increased fraction of light organomineals. Partitioning of soil organic carbon revealed that carbon content is reduced in the heavy fraction than in the light fraction, reflecting that the light fraction contains more fresh and abundant carbon than the passive resistant fraction. It was also found that carbon contents in the overall organic matter, debris, light fraction, and heavy fractions may differ considerably in response to different farming practices.

• 한국식품과학회지
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• 제19권5호
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• pp.441-445
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• 1987

발아중인 대두콩에서의 lipoxygenase의 세포내 위치를 차별 원심 분리법과 밀도 구배법을 이용하여 규명하였다. 차별 원심 분리법을 사용하였을때, lipoxygenase활성은 거의 supernatant fraction에서 나타났으며, 1.5%의 활성만이 particulate fractions에서 나타났다. 밀도 구배법에서는 lipoxygenase와 acid phosphatase의 활성이 1.19, 1.23, $1.25g/cm^3$의 높은 밀도들에서 일치하였으며, 이것은 발아중 가수분해되는 단백질체내에 이 효소가 국재되어지는 것으로 사료되어진다. 다른 세포내 소기관인미토콘드리아, ER, 그리고 glyoxysomes에 lipoxygenase가 존재한다는 증거는 보이지 않았다.

• KSBB Journal
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• 제8권2호
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• pp.97-103
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• 1993

세포질 유전형질의 도입을 성공적으로 수행코자 세질 웅성 불임(eMS; cytoplasmic male sterili­t ty) 계통의 담배 MS(male sterility) Burley 21의 callus tissue에서 cytoplast를 분리시키고 이와 Ni­c cotiana tabacum Burley 64의 mesophyll protoplast 를 PEG방법에 의한 세포융합으로 cybrid cell올 유도할 수 있었다. cytoplast의 분라는 density gradient solution의 osmolarity를 일정하게 하는 것보다 gradient간의 차이가 더 효과적이였으며 분리된 cytoplast의 양은 재료로 이용된 protoplast의 20-30% 정도를 나타 내었다. 또한 cytoplast와 protoplast의 융합은 P PEG농도 50%에셔 효과적이었다.

• 대한수의학회지
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• 제11권2호
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• pp.123-136
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• 1971

이 실험(實驗)은 계혈청(鷄血淸)에 들어 있는 뇌염(腦炎)바이러스에 대한 비특이억제물질(非特異抑制物質)(NSI)의 성상(性狀)과 이의 Acetone-ether와 Kaolin 처리(處理)에 의한 NSI의 제거효력(除去效力)등을 Gel filtration 및 Zonal Centrifugation technique를 이용하여 시험 하였다. 그 결과(結果) (1) 계혈청(鷄血淸)에 들어 있는 비특이 억제물질은 Group A arbovirus 보다 Group B arbovirus에 대하여 더 예민하였다. (2) 연령(年齡)에 의한 NSI의 역가(力價)차이는 없었다. (3) NSI를 제거(除去)하기 위한 Acetone-ether 및 Kaolin 처리는 그 효력면에서 차이가 없었다. (4) 계혈청(鷄血淸)을 일정한 온도(溫度)로 가열(加熱)하면 NSI의 역가(力價)가 상승(上昇) 하였다. (5) NSI의 성분(成分)은 Gel filtraction에서 주로 첫 Peak (IgM)에 있었고, Zonal Centrifugation에서는 원심관의 상층(上層)에 있는 것으로 보아, 이것은 분자량(分子量)은 크고 Density는 낮은 지질단백(脂質蛋白)으로 생각된다. (6) 거위 적혈구에 대한 응집소(NA)는 acetone-ether 처리에 의하여 부분적(部分的)으로 파괴 되었으나 Kaolin 처리에서는 그렇지 못하였고, 10% 거위혈구액으로써 완전 제거할 수 있었다. (7) NA는 Gel filtration 및 Zonal Centrifugation에서 첫 peak (IgM)에 나타났다.

• Clinical and Experimental Reproductive Medicine
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• 제43권4호
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• pp.199-206
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• 2016

Objective: This study was carried out to investigate the correlations of the sperm DNA fragmentation index (DFI) with semen parameters and apoptosis, and to investigate the effects of density-gradient centrifugation (DGC) and magnetic-activated cell sorting (MACS) on reducing the proportion of sperm with DNA fragmentation and protamine deficiency. Methods: Semen analysis and a sperm DNA fragmentation assay were performed to assess the correlations between semen parameters and the DFI in 458 semen samples. Sperm with progressive motility or non-apoptosis were isolated by DGC or MACS, respectively, in 29 normozoospermic semen samples. The effects of DGC or MACS alone and of DGC and MACS combined on reducing the amount of sperm in the sample with DNA fragmentation and protamine deficiency were investigated. Results: The sperm DFI showed a significant correlation (r=-0.347, p< 0.001) with sperm motility and morphology (r=-0.114, p< 0.05) but not with other semen parameters. The DFI ($11.5%{\pm}2.0%$) of semen samples was significantly reduced by DGC ($8.1%{\pm}4.1%$) or MACS alone ($7.4%{\pm}3.9%$) (p< 0.05). The DFI was significantly further reduced by a combination of DGC and MACS ($4.1%{\pm}1.3%$, p< 0.05). Moreover, the combination of DGC and MACS ($1.6%{\pm}1.1%$, p< 0.05) significantly reduced the protamine deficiency rate of semen samples compared to DGC ($4.4%{\pm}3.2%$) or MACS alone ($3.4%{\pm}2.2%$). Conclusion: The combination of DGC and MACS may be an effective method to isolate high-quality sperm with progressive motility, non-apoptosis, high DNA integrity, and low protamine deficiency in clinical use.

• 한국동물학회지
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• 제37권4호
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• pp.597-604
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• 1994

Membranes obtained from the normal human RBC population were separated by continuous sucrose density gradient centrifugation and the density-fractionated membranes were then examined for changes in molecular markers. This study focuses on changes of (i) the membrane protein profile, (ii) differences in membrane-associsted enzyme activities, and (iii) the amount of autologous IgG bound. The following observations were made: (i) ratios for band 4. la over the sum of bands (4. la + 4.Ib) ranged from 0.58 to 0.79 for membranes of lowest density; (ii) significant changes in bound glyceraldehyde-3-phosphate dehydrogenase and acetvlcholinesterase activities were found; (iii) the amounts of autolosous IgG's attached to the red blood cells was highest in the membrane fraction of lowest density.

• Journal of Plant Biology
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• 제28권3호
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• pp.225-232
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• 1985

Intracellular localization and the developmental changes in activities of uricase and allantoinase during germination were investigated with the cotyledons of rape(Brassica napus L.) seedlings. The development anddisappearance of uricase activity took place independently of light, but allantoinase activity was increased by light. The temporal pattern of uricase activity showed that uricolysis was actively taking place in the cotyledons during their early stages of germination. While uricase can be localized in the microbody fraction isolated from crude organelle extracts of the cotyledons by density gradient centrifugation, most of the allantoinase activity found in the microbody fraction did not appear to be an integral part of the microbody.

• Journal of Plant Biology
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• 제30권3호
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• pp.201-203
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• 1987

Total RNA was isolated from two months old wheat, rice, tobacco and sweet potato. The procedure used was simple and provided pure RNA preparation. Lysis of plant tissue in a buffer with guanidine thiocyanate and CsCl density gradient centrifugation separated RNA from the rest of the cellular components. Subsequent cholroform/1-butanol extraction and ethanol precipitation were necessary to ensure contaminant-free RNA preparation. Storage of the lysed plant tissue in the buffer with guanidine thiocyanate preserved the sample for two months without noticeable RNA degradation.

• Korean Chemical Engineering Research
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• 제45권6호
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• pp.611-618
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• 2007

아민기로 코팅된 단분산 폴리스티렌 입자를 제조한 뒤 톨루엔-물로 구성된 유중수 액적(oil-in-water emulsion) 내부에서 입자를 자기 조립(self-assembly)시켜 다양한 다면체(polyhedra) 구조의 콜로이드 클러스터(colloidal cluster)를 제조하였다. 콜로이드 클러스터의 표면에서 솔-젤(sol-gel) 반응을 유발한 뒤 표면이 실리카로 코팅된 복합(composite) 콜로이드 클러스터를 제조할 수 있었고 이를 주형(template)으로 활용하여 고온 소성에 의해 내부의 폴리스티렌 입자를 제거하고 마이크로미터 크기의 다양한 구조의 비구형상 공동 입자(hollow particle)를 제조하였다. 밀도구배원심분리법 (density gradient centrifugation)에 의해 폴리스티렌 구성 입자의 수와 구조가 균일한 콜로이드 클러스터를 제조할 수 있었으며 표면 솔-젤 반응에 의해 비구형상 구조의 공동 입자를 제조하였다.