[Ultracentrifugation in virus diagnosis]

Ultracentrifugation has assumed growing importance in virus diagnosis as a technique by which to concentrate and purify viruses for immediacy diagnosis on the basis of electron microscopy as well as for purely virological and serological tests. Ultracentrifugation has proved to be helpful for sizeable improvement of sensitivity for detection, which, in turn, has been conducive to time saving. The preparational ultracentrifuge enables also direct diagnosis by determination of isodensities and sedimentation coefficients of viruses and their components. Examples are mentioned, in that context, such as FMD virus, virus of vesicular swine disease, virus of larynx papillomatosis of man, and goose influenza virus. An account is given of isodensities and sedimentation coefficients of animal viruses.