Scanning electron microscopic observation on intracellular structures of ion-etched materials.

Ion-etching technique on the cracked surface of biological material may give a plastic visualization of intracellular structures under the scanning electron microscope, because membraneous structures in the cell are generally etch-resistant and the cytoplasmic matrix is easily ion-etched. Mild ion-etching using low voltage was applied to the cells of the pancreas. Nuclear pores were clearly disclosed but were enlarged slightly in the process of etching. Endoplasmic reticulum with ribosomes, Golgi apparatus, mitochondria, some filamentous structures and crystalline inclusions (B cell granules) were also effectively disclosed by ion-etching technique. It is necessary, however, to compare the etched specimens carefully with non-etched ones to determine whether given structures observed are intrinsic ones or artifacts caused by etching.