Observations on the Rous virus; purification and identification of the particles from solid tumours.

M A Epstein

doi:10.1038/bjc.1958.30

Abstract

Observations on the Rous Virus; Purification and Identification of the Particles from Solid Tumours

Highlights

Experiments are described in which a fluorocarbon (CF2Cl-CC12F) was used to prepare suspensions of the particles which occur in association with the cells of the Rous sarcoma
Nodules of solid Rous tumours were grown on the chorioallantoic membranes of chick embryos and their virus-like particles were separated from host cell constituents at a water-fluorocarbon interface; the suspensions were subjected to high speed centrifugation for one hour and the pellets obtained were fixed, embedded and sectioned for electron microscopy
Direct observation of the sectioned pellets with the electron microscope has been used as a check on their purity

Summary

Methods

Tumour.-The Rockefeller Institute strain of the Rous No 1 fowl sarcoma which was used has been described previously (Epstein, 1956a). It was passed in series every 7 days by the inoculation of 05 ml. The birds were between 6 and 7 weeks old when used for the titrations; in the tumour passages 6 to 8 week old birds were inoculated because of the exigencies of supply. Eggs.-Fertile chickens' eggs were obtained throughout from the same source; they were used after the embryos had been incubated for 8 to 9 days at 370 C. The inoculation of the fowl used in the titrations and their subsequent examination was done as in previous work (Epstein, 1956a). The tumours were passed and the titrations carried out with strict aseptic technique; tests for the presence of contaminating bacteria were negative.

Results

Discussion

Conclusion