Ruiz T, Erk I, Lepault J
Centre de Génétique Moléculaire, CNRS, Gif-sur-Yvette, France.
Biol Cell. 1994;80(2-3):203-10. doi: 10.1111/j.1768-322x.1994.tb00931.x.
A decade after the development of electron cryo-microscopy for vitrified specimens, its advantages and limitations are analysed. Indeed, recent work carried out by different laboratories strengthens the idea that electron cryo-microscopy might soon be an alternative method to X-ray crystallography and NMR techniques for determining the structure of biological assemblies with both high spatial and temporal resolutions. High pressure freezing allows vitrification of larger volumes of biological suspensions. Thick vitrified objects can be cryosectioned. Electron cryo-microscopy of the sections gives images having a resolution better than 2 nm. Although the high resolution imaging mode under low dose conditions is not yet fully understood, microscopes are being developed to provide better and better images. Image averaging is being facilitated by the development of both crystallization and computer methods. Thus, we can expect that electron microscopy will soon become a potential technique for structural determination at atomic resolution. Finally, much effort is being devoted to improving the temporal resolution of electron cryo-microscopy. Soon, we may be able to observe molecules during their biological activity.
在用于玻璃化标本的电子冷冻显微镜技术发展十年后，对其优缺点进行了分析。实际上，不同实验室最近开展的工作强化了这样一种观点，即电子冷冻显微镜技术可能很快成为X射线晶体学和核磁共振技术的替代方法，用于在高空间和时间分辨率下确定生物组装体的结构。高压冷冻可使更大体积的生物悬浮液玻璃化。厚的玻璃化物体可以进行冷冻切片。对切片进行电子冷冻显微镜观察可得到分辨率优于2纳米的图像。尽管低剂量条件下的高分辨率成像模式尚未完全被理解，但正在开发能提供越来越好图像的显微镜。结晶和计算机方法的发展促进了图像平均化。因此，我们可以预期电子显微镜很快将成为一种用于原子分辨率结构测定的潜在技术。最后，人们正在投入大量精力来提高电子冷冻显微镜的时间分辨率。很快，我们或许就能在分子的生物活性过程中对其进行观察。
