cryoelektronmikroszkópia

Cryo-electron microscopy, often abbreviated as cryo-EM, is a powerful technique used to determine the three-dimensional structure of biological macromolecules, such as proteins and viruses, at near-atomic resolution. The fundamental principle involves flash-freezing a sample in a thin layer of vitreous ice. This rapid freezing prevents the formation of damaging ice crystals, preserving the native structure of the molecules.

Once frozen, the sample is then imaged using an electron microscope. Because the sample is so thin, electrons can pass through it with minimal scattering, allowing for the collection of a large number of 2D projection images of the molecules from different orientations. These images are then computationally processed using sophisticated algorithms. By averaging thousands or even millions of these 2D images, and by classifying them based on their orientation, a 3D reconstruction of the molecule can be generated. This 3D map can then be used to build an atomic model of the biological structure, providing invaluable insights into its function. Cryo-EM has revolutionized structural biology, enabling the study of complex and dynamic biological assemblies that were previously inaccessible.