Preparation Methods for EM Studies of Polymers

Abstract

Polymers are organic materials, and most of the preparation methods for transmission electron microscopy (TEM) are much the same as for biological specimens. Bulk samples are cut in the ultramicrotome, and latex particles are dropped onto a Formvar-coated grid. However, the staining possibilities of polymers are limited. Polymers mainly consist of saturated hydrocarbon, and unlike biomaterial there are few reactive groups for staining. This has two consequences for the microscopist: it is difficult to obtain contrast, and the sample is very beam-sensitive. Biological samples are also organic material and sensitive to the beam, but the staining process converts them into materials that are usually stable to the beam.