ELECTRON DENSITOMETRY OF STAINED VIRUS PARTICLES

Electron Densitometry of Stained Virus Particles

Methods are described for determining the relative mass of particles in electron microscope specimens through the measurement of photographic densities in recorded images. These methods were applied to a quantitative study of the amounts of electron stains that could be associated with the particles of tomato bushy stunt virus (BSV) and tobacco mosaic virus (TMV). In the pH range above 2 where ...

Electron Microscopy of Fowl Pox Virus

Automatic Identification of Icosahedral Virus Particles in Electron Micrographs

Three-dimensional reconstruction of the structure of spherical viruses at high resolution (5 to lOA) requires automatic identification of virus particles in electron micrographs. Existing methods are extremely sensitive to noise from various sources present in micrographs and the results reported are only modestly successful. In this paper we introduce the Crosspoint Method, a set of new algori...

Detection of virus particles by electron microscopy with polyacrylamide hydrogel.

The use of lyphogel to concentrate the number of virus particles in specimens for electron microscopic examination was studied in parallel with ultracentrifugation. One hundred faecal and urine samples were compared. Both methods had a similar sensitivity. Lyphogel was economical, simple, and rapid in use; in contrast to ultracentrifugation, it required relatively little material. The procedure...

Centrifugal sedimentation of virus particles for electron microscopic counting.

Centrifuge cells with conical chambers were provided by using special inserts for the stainless-steel tubes that fit the Spinco SW-39 rotor. Particulate material, centrifuged in these cells, was collected on carbon-coated glass discs. These discs were exposed to OsO(4) vapor, dehydrated in graded alcohols, air-dried, and metal-shadowed. The metal-shadowed carbon film was floated from the glass,...