Creative Biolabs has focused on structure determination for years. Our seasoned scientists have established an advanced structure determination platform to provide various services. We can perform high-quality tailored structure determination services using cryo-electron microscopy to meet all your demands.
Cryo-electron microscopy is widely known as cryo-EM or electron cryomicroscopy, and it's a form of transmission electron microscopy (TEM). Usually, the samples are researched at cryogenic temperatures when using cryo-EM, which is gradually turning into a popular tool to investigate the formation of cells, viruses and protein fittings at molecular resolution. What's more, cryo-EM density maps are being commonly combined with NMR spectroscopy and X-ray crystallography. Therefore, atomic-resolution patterns of intricate, action molecular assemblies can be accomplished. Unlike X-ray crystallography, which needs to crystallize the specimen, cryo-EM enables the observation of specimens in their natural state. In a traditional cryo-EM, the image contrast of such phase objects is mostly produced by a combination of lens aberration and defocus. In frequency space, the data are oriented by the sinusoidal contrast transfer function (CTF) and are damped by exponential envelope functions, inducing poor contrast at low frequency, a fall-off in the signal at high frequency, and the reduction of information at the nodes of the CTF.
Figure 1. Cryo-EM structure determination of the caspase-1CARD filament. (Lu 2016)
Advantages of Cryo-electron Microscopy
Due to the extensive injury arising from the interaction of electrons and organics, the atomic-resolution imaging of individual viruses, proteins and cells under natural environment is impossible through a conventional electron microscope. Cryo-EM is the first method used in “high-resolution” electron microscopy to solve this issue, in which imaging can be finished through frozen specimens maintained at either liquid nitrogen or liquid helium temperatures.
Biological Specimens Imaging of Cryo-electron Microscopy
The biological material is expanded on an electron microscopy grid and kept in a frozen-hydrated condition by quick freezing, generally in liquid ethane near liquid nitrogen temperature. Specimens are able to be brought into the high-vacuum of the electron microscope column via keeping them at liquid nitrogen temperature or colder. The sub-nanometer or near-atomic resolution of viruses and protein complexes have been worked out by the cryo-EM images. Meanwhile, these results provide novel insights into the structure and biology of those great assemblies.
Based on the advanced drug discovery platform and a professional scientific team devoted to the structure determination studies, Creative Biolabs is confident in performing consummate structure determination services by using cryo-electron microscopy. For more detailed information, please feel free to contact us or directly sent us an inquiry.
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