Living cell super-resolution fluorescence imaging technology was invented

As the first Chinese female scientist to receive the "Genius Award" from the MacArthur Foundation of the United States, Professor Zhuang Xiaowei has achieved many important achievements, especially in the field of biophysical microscopy. Recently, Professor Zhuang Xiaowei published the title "Fast, three-dimensionalsuper- The paper "resolutionimagingoflivecells" introduces its research team's latest advances in super-resolution cell imaging research - living cell super-resolution fluorescence imaging technology, published in the online version of NatureMethods. .

Conventional optical microscopes are limited by the wavelength of light and are indistinguishable for objects below 200 nm. Although electron microscopy can achieve nanometer-scale resolution, current is prone to sample damage, so the number of samples that can be observed is quite limited. Although molecular biologists can affix a number of target proteins to fluorescent labels, these proteins are often squeezed together and difficult to distinguish under the microscope.

In recent years, the development of high-resolution fluorescence microscopy has enabled researchers to observe the extension of cell protrusions from the nanoscale, thus announcing the end of the fuzzy agglomeration era of the size range of 200-750 nm. For example, a photosensitive localization microscope (PALM) can be used to observe nanoscale organisms. Compared with electron microscopy, there is a clearer contrast. If different proteins are labeled with different fluorescent labels, the interaction between proteins can be further studied.

Zhuang Xiaowei's research team has been studying how to use a photosensitive switch probe to achieve single-molecule illumination technology. They hope to use a light-sensitive switch to temporarily separate several molecular images that were originally overlapped, so that a single-molecule image can be obtained, thereby improving resolution.

In 2004, Zhuang Xiaowei's research team accidentally discovered that certain cyanine dyes have light-controlled switches, that is, by using different colors of light, they can be randomly activated into a fluorescent state and deactivated into a dark state. Since then, Zhuang Xiaowei has begun to study these light-controlled probes, which are used to temporarily separate overlapping images of individual molecules in space to improve resolution.

In the article "Nature-Methodology", Zhuang Xiaowei's research group named a stochastic optical reconstruction microscope (STORM). DNA molecules and DNA-protein complex molecules can be seen with a resolution of 20 nm using STORM. This method is based on the fluorescence probe and centroid localization principle of the photon controllable switch. Under the double laser excitation, the fluorescent probe emits light randomly, and the ultra-high resolution image is formed by molecular positioning and molecular position overlap reconstruction. The spatial resolution is currently Up to 20nm.

Although STORM can provide higher spatial resolution, imaging time often takes a few minutes, and it can not meet the real-time visual imaging needs of living. Live cell imaging is important, but achieving high-resolution imaging without affecting the normal life of the cell is not easy. In this article, Zhuang Xiaowei's research group reported the results of ultra-high resolution fluorescence imaging of living cells through STORM with high spatial and temporal resolution.

The researchers directly or indirectly (via SNAP) label the proteins with a photosensitive switch dye to obtain ultra-high-resolution imaging of living cells in both 2D and 3D. These imaging results will facilitate further analysis of the activity of living cells, and this method is also A window was opened for scientists to analyze the ultrastructure of living cells.

Machine Dried Kelp

Rongcheng Jingyi Oceanic Technology Company Limited , https://www.jingyifoods.cn