Method for the Observation of Macromolecules with the Electron Microscope Illustrated with Micrographs of DNA

Abstract

Macromolecules are supported on the surface of freshly cleaved mica where they are shadow-cast with platinum which is then backed with thin films of silicon monoxide and collodion and stripped for examination with the electron microscope. The extreme smoothness of the substrate makes possible the observation of individual molecules. Micrographs are shown of desoxyribose nucleic acid (20A thick) and polymerized adenosine monophosphate (10 to 20A thick).