制药技术

Low temperature scanning electron microscopy (Cryo-SEM) has become an established technique for capturing and observing biological samples close to their natural state. It is a method of choice, where the traditional sample preparation (e.g. critical point drying) causes unwanted changes in the sample structure. A Cryo-SEM workflow typically involves sample fixation using either flash-freezing in a liquid nitrogen slush or high-pressure freezing. The frozen samples are then transferred under vacuum to a cryo sputter coater, where they are coated with a conductive layer of metals or carbon. Finally, the samples are inserted into a SEM chamber equipped with a cryo-stage and observed in high vacuum environment.