Abstract
This work presents advanced resistance mapping techniques based on Scanning Electron Microscopy (SEM) with nanoprobing systems and the related embedded electronics. Focus is placed on recent advances to reduce noise and increase speed, such as integration of dedicated in situ electronics into the nanoprobing platform, as well as an important transition from current-sensitive to voltagesensitive amplification. We show that it is now possible to record resistance maps with a resistance sensitivity in the 10W range, even when the total resistance of the mapped structures is in the range of 100W. A reference structure is used to illustrate the improved performance, and a lowresistance failure case is presented as an example of analysis made possible by these developments.
Evidence is presented that cytoskeletal structures (actin filaments, intermediate filaments, and microtubules) can be resolved by scanning electron microscopy after osmium impregnation of biological material, using thiocarbohydrazide as a ligand, followed by critical-point drying. These different classes of filaments or tubules can be identified both as purified protein polymers and as structured organelles within cryofractured or detergent-extracted cells.
Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.
High resolution scanning electron microscopy of isolated and in situ cytoskeletal elements.