Scanning electron microscopic observations on deembedded biological tissue sections: Comparison of different fixatives and embedding materials

Conventional plant histological specimens fixed in formalin‐acetic acid‐alcohol, chromic acid‐acetic acid‐formaldehyde, or glutaraldehyde‐osmium and embedded in either paraffin or plastic are examined as possible rapid methods for providing an alternative image of cellular structure by using scanning electron microscopy. Using the mitotic figures of actively growing onion root tips as a study specimen, the organization of the nucleus and spindle apparatus is reasonably well preserved as compared with isolated mitotic spindles and studies of mitosis in endosperm tissue. Relief of internal structure in this technique is obtained through the coagulant nature of the fixative. Used judiciously, this technique can reveal aspects of the three‐dimensional nature of internal tissue structure that may otherwise be difficult to discern.