The interpretation of radiation damage measurements with electron diffraction of organic materials at very low temperatures

Cryotechniques in Biological Electron Microscopy

“…The results of this study agree well with previous observations (Knapek et al 1984;Wade 1984) that the electron diffraction patterns of crystalline protein and hydrocarbon specimens last approximately three to five times longer when cooled to about 150 K from room temperature. The study involved two standardized crystalline samples, paraffin and bacterial purple membrane, examined following the same standard protocol in all laboratories.…”

“…Inadequate contact may cause a large temperature difference (tens of degrees) between specimen and holder, and may give rise to more severe damage, radiolytic and mechanical, due to charging effects (Knapek et al 1984). Inadequate contact may cause a large temperature difference (tens of degrees) between specimen and holder, and may give rise to more severe damage, radiolytic and mechanical, due to charging effects (Knapek et al 1984).…”

“…The excitement about these promising results later turned to disappointment when it was found (Lepault et al 1983c) that the earlier results were erroneous. It seems now that the most that can be expected is an improvement by a factor of three to five, and that this can usually be achieved at liquid nitrogen temperatures when precautions are taken to limit beamneating and charging effects (Knapek et al 1984;Wade 1984). It seems now that the most that can be expected is an improvement by a factor of three to five, and that this can usually be achieved at liquid nitrogen temperatures when precautions are taken to limit beamneating and charging effects (Knapek et al 1984;Wade 1984).…”

High‐conductivity amorphous TiSi substrates for low‐temperature electron microscopy

“…Studies have shown that carbon films have a very low electrical conductivity at low temperature, with resistivity rising above 1 x lo9 pQm between 6 and 7 K (Lamvik et al, 1989b). To remedy the problem of electrical charging in thin carbon films at low temperature, thin evaporated titanium films (Collins & Parker, 1977) were adopted for use at low temperature (Lamvik et al, 1989a). Measurements of electrical properties in the thin films showed that the titanium supports had a much lower resistivity, of the order of 2.7-2.9 pQm, than that of carbon films at low temperature (Lamvik et al, 1989a).…”

“…To remedy the problem of electrical charging in thin carbon films at low temperature, thin evaporated titanium films (Collins & Parker, 1977) were adopted for use at low temperature (Lamvik et al, 1989a). Measurements of electrical properties in the thin films showed that the titanium supports had a much lower resistivity, of the order of 2.7-2.9 pQm, than that of carbon films at low temperature (Lamvik et al, 1989a). While the high electrical conductivity is an advantage, pure metal films such as titanium display a microcrystalline structure that produces a distracting background in high-magnification electron micrographs ( Fig.…”