The use of radio frequency sputter ion etching and scanning electron microscopy to study the internal structure of biological material

Abstract

Radio frequency sputtering has been used to ion etch samples of soft biological material prior to observation in the scanning electron microscope. Initial studies have been made with normal and abnormal human red blood cells given a prior fixation in glutaraldehyde. Etching has been carried out in argon, hydrogen, or oxygen, each of which accentuates different structural features in and beneath the cell membrane. Abnormal cells, such as those from a patient with sickle cell disease, show a more etch-resistant membrane and a coarser internal structure than normal cells. The technique is being extended to the study of a wider range of cytological material.