Give+a+brief+description+about+the+limitations+or+disadvantages+of+using+SEM

One disadvantage of the scanning electron microscope (SEM) is that it is normally not be able to observe objects that produce any significant amount of vapor when placed in a vacuum. Because of this limitation, biological samples must be dried, and many samples like grease, adhesives, liquids, foods, gels, and others semisolids cannot be examined. Some vapor-producing samples can be examined using cryogenic SEM.