Photoelectron imaging of cells: photoconductivity extends the range of applicability.

Photoelectron imaging is a sensitive surface technique in which photons are used to excite electron emission. This novel method has been applied successfully in studies of relatively flat cultured cells, viruses, and protein-DNA complexes. However, rounded-up cell types such as tumor cells frequently are more difficult to image.

Photoelectron imaging of viruses and DNA: evaluation of substrates by unidirectional low angle shadowing and photoemission current measurements.

Photoelectron imaging (photoelectron emission microscopy, PEM or PEEM) is a promising high resolution surface-sensitive technique for biophysical studies. At present, image quality is often limited by the underlying substrate. For photoelectron imaging, the substrate must be electrically conductive, low in electron emission, and relatively flat.

A computer-aided control, design and image-processing system for electron microscopes.

A computer-control system for electron microscopes is described. The aim is to reduce a complex series of vacuum-system controls to a menu-driven program that simplifies the operation of the microscope. The system also incorporates image processing, notebook, computer-aided design, and communication functions.

Biological applications of photoelectron imaging: a practical perspective.

Photoelectron imaging is finding a promising niche in the study of biological specimens. The features of photoelectron imaging that contribute to its uniqueness for this application are described. Image formation and the major contrast mechanisms of photoelectron microscopy, material contrast and topographical contrast are reviewed and illustrated with examples of photoelectron images of cultured cells and of DNA.