@article{mbs:/content/journal/jgv/10.1099/0022-1317-33-3-403, author = "Bronson, D. L. and Elliott, A. Y. and Ritzi, Donna", title = "A Comparison of Four Methods Used to Concentrate Rous Sarcoma Virus from Tissue Culture Fluids", journal= "Journal of General Virology", year = "1976", volume = "33", number = "3", pages = "403-410", doi = "https://doi.org/10.1099/0022-1317-33-3-403", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-33-3-403", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "SUMMARY Three methods of pelleting, pelleting followed by Pronase treatment, polyethylene glycol (PEG)-Pronase, and diaflo ultrafiltration (diafiltration) were used to concentrate RSV (RAV-1) from tissue culture fluids. Sucrose-gradient fractions containing virus preparations which had been concentrated by diafiltration or pelleting were heavily contaminated with amorphous debris. This debris was not present in similar, gradient-purified preparations that had been concentrated by the PEG-Pronase or pellet-Pronase methods. Maximum recovery of radiolabelled virus particles and virion-associated RNA-dependent DNA polymerase activity was obtained in gradient fractions containing virus concentrates prepared by the pellet-Pronase and PEG-Pronase methods. Although there were slight differences in recovery by these two methods, the advantages of the PEG-Pronase method make it the preferred method, especially when large volumes of tissue culture fluids are used.", }