查看完整版本: 3D microscope obtains nanoscale resolution

3D microscope obtains nanoscale resolution

[color=Blue][b][NanoST News]The highest resolution 3D images of the inside of single cells have been generated by scientists at the Max Planck Institute in Germany. The group says that its scanning fluorescent microscope obtains a spatial resolution far below the wavelength of light, allowing it to image the interior of cells with unprecedented detail.[/b][/color]j#L P~E

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7TQE~%l [color=Gray]Unprecedented detail: (left) the 40-45 nm diameter focal fluorescent spot of the team's isoSTED microscope as compared with the focal fluorecsent spot of a (high end) confocal microscope (shown are sections containing the optic axis). The fundamental reduction in size of the fluorescent spot enables a much higher spatial resolution in 3D. (right) mitochondrion imaged with nanoscale resolution. The TOM20 mitochondrial complex is shown in red and a protein from the inner part of the mitochondrion shown in green. (Image credit: Stefan Hell)[/color].a1@:M_Tq

jsf"s(X%O`w "We have produced the smallest focal spots that have been attained so far in a scanning fluorescent microscope, and thus attained the best 3D resolution inside a transparent object such as a cell," Stefan Hell, from the Department of NanoBiophotonics in Göttingen, told optics.org. "Contrary to previous systems, the focal spot, which measures 40–45 nm in diameter, is both spherical and of subdiffraction dimensions enabling isotropic 3D resolution on the nanoscale."|YF{ C,sTiZ


M0t`S9I6J The resolution of a standard confocal system is limited to over 200 nm in the focal plane and over 500 nm along the optic axis. "We have achieved a resolution of 40–45 nm in all directions and this can be improved even further since our scheme allows further confinement of fluorescent spot (i.e. the effective PSF of the microscope)," commented Hell.
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iJQR:`1K_ The group's setup is a lens-based fluorescence microscope that merges the fundamentals from two existing microscopy techniques. "We have developed an effective microscopy scheme called isoSTED, which combines elements of stimulated emission depletion (STED) and 4Pi microscopy to compress the fluorescent spot to subdiffraction dimensions," explained Hell.
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G p:?"c'@2rl X In STED microscopy, very short laser pulses excite a fluorescent tag attached to the sample under observation. This excitation pulse is immediately followed by a depletion pulse, tuned to an emission line of the fluorescent tag. The depletion pulse causes stimulated emission, which moves electrons from the excited state from which fluorescence occurs to a lower energy state. This decreases the effective spot size of the excited region resulting in higher resolution imaging.W?Rq4C+|(C

;o/]m mcG0p The idea behind 4Pi microscopy is to illuminate the sample with a pair of synchronized laser pulses in such a way that the pulses interfere constructively. This is equivalent to increasing the total aperture of the system.\ E
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8Z,g+Sh!~ QCR#m The researchers presented their results in [url=http://www.nature.com/search/executeSearch?sp-q=hell&sp-c=10&sp-x-9=cat&sp-s=date&sp-q-9=NMETH&submit=go&sp-a=sp1001702d&sp-sfvl-field=subject%7Cujournal&sp-x-1=ujournal&sp-p-1=phrase&sp-p=all]Nature Methods[/url].
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Source: optics.org

据6月6日的《科学》（Science）杂志报道说，一种新型的显微镜能够展示高清晰度、多色彩的三维画面，它比以前用的传统显微镜能揭示出更多的细节。Lothar Schermelleh及其同事研发了这种叫做三维结构照明（3D-SIM）的新成像技术，并用它在大约100纳米的分辨率下来探索哺乳动物的细胞核。 zEYvKX
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最好的传统显微镜的分辨率可以放大至200-300纳米，但是研究人员利用这一新型的3D-SIM来捕捉多色彩、三维画面的细胞特征，他们甚至能够给细胞不同的成份标记上不同的颜色，这是一个前所未有的壮举。这一新的发展使得分子细胞生物学有了令人感兴趣的新的视角，而它又不需要任何非常规的设备，并且也并不比一台标准的商业用显微镜更难使用。（来源：EurekAlert!中文版）T"a3e4Mwa&`5~

Zs\dX\4B （《科学》（Science），Vol. 320. no. 5881, pp. 1332 - 1336，Lothar Schermelleh，John W. Sedat）