The Process of Infection with Bacteriophage ΦX174: VII. Ultracentrifugal Analysis of the Replicative Form
- Creators
- Burton, Alice
- Sinsheimer, Robert L.
Abstract
A procedure is described for the preparation of a purified ΦX174 replicative form DNA. Ultracentrifugal analyses, zone sedimentation and density gradient of this DNA, both when native and when denatured, are described. At neutral pH, two major sedimentation components in the purified replicative form of 21·2 s (I) and 16·2 s (II) (as the sodium salts) are observed. At alkaline pH, in high ionic strength medium, or at neutral pH in formamide, (I) gives rise primarily to a rapidly sedimenting component, the denatured double-stranded DNA ring. Under the same conditions, (II) gives rise to infective single-stranded DNA rings. It is concluded that (I) is the closed double-strand DNA ring, whereas (II) is composed of double-stranded DNA rings in which one strand is open.
Additional Information
© 1965 Elsevier Ltd. Received 8 June 1965, and in revised form 17 August 1965. We thank Mrs Shizuko Yagi and Mrs Gloria Davis for their assistance with the infectivity assays; Dr O. E. Dowell for his helpful discussions; and Mr James Strauss, who performed the experiment described in Fig. 7. During part of this work, one of us (A. B.) was a postdoctoral fellow of the U.S. National Institutes of Health. This research was supported in part by grant RG6965 from the U.S. Public Health Service.Additional details
- Eprint ID
- 68460
- Resolver ID
- CaltechAUTHORS:20160617-074730672
- RG6965
- U.S. Public Health Service (USPHS)
- NIH Postdoctoral Fellowship
- Created
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2016-06-17Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field