EM-CRYO

cryo – electron microscopy or CRYO-EM
Unlike an optical microscope, which uses light, the electron microscope accelerates and concentrates a beam of electrons to create an image of the sample to be observed. The problem is that this technique requires chemically fixing and dehydrating the samples, which degrades their quality. This is the  classic chemical preservation treatment of biological samples.

To avoid this chemical process, cryo-ME consists in freezing the samples very quickly at -190 ° C in liquid ethane, which preserves their structure (physical treatment by cold).