hide
Free keywords:
Biological specimen preparation; Electron microscope examination of materials; Molecular biophysics; Proteins; Surface energy; Surface tension; Interactions with radiations at the biomolecular level [A8715M]; Biophysical instrumentation and techniques [A8780]
Abstract:
Data collection by electron diffraction and electron microscopy at high resolution and high tilt angles requires thin crystals of biological macromolecules that are flat to at least 1 degrees , and perhaps less than 0.2 degrees , over areas as large as 1 mu m/sup 2/ or more. In addition to determining empirically by electron diffraction experiments whether sufficiently flat specimens can be prepared on various types of modified or unmodified carbon support films, the authors have begun to use other techniques to characterize both the surfaces involved and the interaction of the specimen with these surfaces. In the specific case of large, monolayer crystals of bacteriorhodopsin prepared as glucose-embedded specimens on hydrophobic carbon films, it was concluded that the initial interfacial interaction involves adsorption of the specimen to the air-water interface rather than adsorption of the specimen to the substrate. (62 References).
