2012 Fiscal Year Final Research Report
Development of direct observation method of bio-molecules by using environmental phase plate transmission electron microscopy
| Project/Area Number |
22540418
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics/Chemical physics
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
MINODA Hiroki 東京農工大学, 大学院・工学研究院, 准教授 (20240757)
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| Project Period (FY) |
2010 – 2012
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| Keywords | 環境制御TEM / 生物分子 / 位相差像 |
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| Research Abstract |
We have been developing a combination method for environmental TEM (E-TEM) and phase-plate TEM (P-TEM) that enables direct observations of the structure of biological molecules in aqueous solution. It is clearly demonstrated that the biological molecules in a water layer can be imaged by the combined method without any stain. The spatial resolution obtained in the present study was about 10 nm. This should be improved by using energy filtering. The image contrast of the specimen in water was reduced in comparison with that in vacuum. A model calculation that includes the effects of beam broadening, intensity decrease, and background increase caused by scattering from the water layer around the specimen shows that an increase in the thickness of the water layer reduces the contrast, intensity, and resolution of the image.
A carbon sandwitch environmental cell for wet specimen was developed for environmental transmission electron microscopy. A plastic film with many holes was used to form carbon capsules. The samples and experimental solution are enclosed in the capsules made of the spacer and two carbon films. The thickness of water layer can be controlled by changing conditions to prepare the plastic spacers. The quality of the images was improved comparing with our previous environmental cell which can circulate gas around samples and2nm resolution was obtained by using loosely condensed DNAs.
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