The application of scanning electron microscopy to biological research

Abstract

Abstract The various modes of specimen signal acquisition presently available on the scanning electron microscope permit both morphological and analytical studies to be carried out on the specimen. The advantage of the scanning electron microscope is that it provides an information-rich image at resolutions determined by electron optical consideration. This is because of the unique separation of the process of information localization from the information transfer and display. The application of cathodoluminescence and X-ray microanalysis to biological investigations is only now beginning, and the preliminary studies show that these two techniques are going to rapidly provide molecular and elemental information about specimens. Although the ion beam etching process is not completely understood, thus making valid interpretations rather difficult, this process coupled with in situ visualization in the microscope will provide a valuable tool in the study of biological material. The comparative ease of specimen preparation for all but the most labile biological material coupled with the ability to examine specimens at low accelerating voltages without a surface coating permits a rapid examination of the surface features of plant and animal material at resolutions of better than 100 nm. More critical preparative procedures are necessary when examining labile biological materials, and details are given of some preliminary studies on the examination of samples at liquid nitrogen temperatures. The simple preparative technique involved coupled with the versatility and controlled sensitivity of the stage modules allows rapid visualization of the specimens.