Direct observation of unstained wet biological samples by scanning-electron generation X-ray microscopy
Direct observation of unstained wet biological samples by scanning-electron generation X-ray microscopy
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DOI：
10.1016/j.bbrc.2009.11.031
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发表时间：
2010-01-01
影响因子：
3.1
通讯作者：
Ogura, Toshihiko
中科院分区：
文献类型：
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作者：
Ogura, Toshihiko
在生物物理和化学领域，纳米级分辨率的分析工具是不可或缺的。软X射线显微镜是一种合适的工具，它为生物样品的湿样品提供了高空间分辨率的可见光，而位于碳(284 eV；4.3 nm)和氧(540 eV，2.3 nm)吸收边之间的水窗波长的X射线提供了水中生物样品的高对比度成像。在X射线显微镜的类型中，使用同步辐射光源和衍射波带片的透射式X射线显微镜具有最高的空间分辨率。接近15-10海里。然而，测量生物样品中的蛋白质和蛋白质复合体需要更高的分辨率：因此，需要一种使用简单光源的具有更高分辨率的新型X射线显微镜。在这里，我们报告了一种新型的扫描电子产生X射线显微镜(SGXM)，它演示了对未染色的湿生物样品的直接成像。我们将湿酵母放置在两层氮化硅(Si3N4)薄膜之间的香料中。用加速电压为5keV、电流为1.6nA的扫描电子束照射钛(Ti)包覆的氮化硅(Si3N4)薄膜，通过放置在样品下方的X射线光电二极管(PD)探测软X射线信号。SGXM理论上可以达到优于5 nm的分辨率。该方法可以方便地用于各种潮湿的细菌生物样品。病毒和蛋白质复合体。(C)2009 Elsevier Inc.保留所有权利
Analytical tools of nanometre-scale resolution are indispensable in the fields of biology physics and, chemistry One suitable tool, the soft X-ray microscope, provides high spatial resolution of visible light for wet specimens For biological specimens, X-rays of water-window wavelength between carbon (284 eV; 4.3 nm) and oxygen (540 eV, 2.3 nm) absorption edges provide high-contrast imaging of biological samples in water. Among types of X-ray microscope, the transmission X-ray microscope using a synchrotron radiation Source with diffractive zone plates offers the highest spatial resolution. approaching 15-10 nm. However even higher resolution is required to measure proteins and protein complexes in biological specimens: therefore, a new type of X-ray microscope with higher resolution that uses a simple light source is desirable. Here we report a novel scanning-electron generation X-ray microscope (SGXM) that demonstrates direct imaging of unstained wet biological specimens. We deposited wet yeasts in the spice between two silicon nitride (Si3N4) films. A scanning electron beam of accelerating voltage 5 keV and current 1.6 nA irradiates the titanium (Ti)-coated Si3N4 film, and the soft X-ray signal from it is detected by an X-ray photodiode (PD) placed below the sample The SGXM can theoretically achieve better than 5 nm resolution Our method call be utilized easily for various wet biological samples of bacteria. viruses, and protein complexes. (c) 2009 Elsevier Inc. All rights reserved