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Independent Functions of Viral Protein and Nucleic Acid in Growth of Bacteriophage. September 20, 1952.

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Title:	Independent Functions of Viral Protein and Nucleic Acid in Growth of Bacteriophage [13 of 18]
Creator:	Chase, Martha
Contributor:	Hershey, Alfred Day, 1908
Publisher:	Journal of General Physiology
Date:	1952-09-20
Subject:	Molecular biology Molecular genetics
Description:	From the Journal of General Physiology Vol. 36, No. 1.
Type:	Text
Format:	text/plain
Language:	en
Identifier:	hersheychase-pg13.jpg
Source:	Master scanned with Epson GT-10000+ flatbed scanner at 600 dpi.
Rights:	http://osulibrary.orst.edu/specialcollections/coll/pauling/dna/copyright.html
Full Text:	A. D. HERSHEY AND MARTHA CHASE 51 teria adsorbing lysing phage but not phage progeny. The latter test shows that the Sib is not contained in the phage progeny, and explains the fact that the Sib in early lysates not containing progeny behaves in the same way. The specificity of the adsorption of Sib-labeled material contaminating the phage progeny is evidently due to the lysing phage, which is also adsorbed much more strongly to strain H than to B/2, as shown both by the visible re- duction in Tyndall scattering (due to the lysing phage) in the supernatants of the test mixtures, and by independent measurements. This conclusion is further confirmed by the following facts. TABLE VII Adsorption Tests with Uniformly S'5-Labeled Phage and with Products of Their Growth in Not-Radioactive Vedium Per cent adsorbed Unifornily labeled 3aa phage Products of Phage progeny Adsorbing bacteria -{- UV-h I No UV-h lysis at (Maximal yield) gas sat t= to sat Phage gas Sensitive (I3) ...................... 84 l 79 78 96 86 Resistant (B/2) . ... . . .............. 15 11 46 49 10 Resistant (B/2h) .............. . . . . . 13 12 29 28 8 The uniformly labeled phage and the products of their growth are respectively the seed phage and the high speed sediment fractions from the experiment shown in Table V1. The uniformly labeled phage is tested at a low ratio of phage to bacteria: +UV-h means with added UV-killed is mutant in equal concentration to that present in the other test materials. The adsorption of phage is measured by plaque counts of supernatants, and also sedi- ments in the case of the resistant bacteria, in the usual way. 1. If bacteria are infected with Sib phage, and then lysed near the midpoint of the latent period with cyanide alone (in salt-poor broth, to prevent read- sorption of S'S to bacterial debris), the high speed sediment fraction contains Sib that is adsorbed weakly and non-specifically to bacteria. 2. If the lysing phage and the S16-labeled infecting phage are the same (T2), or if the culture in salt-poor broth is allowed to lyse spontaneously (so that the yield of progeny is large), the S35 in the high speed sediment fraction is adsorbed with the specificity of the phage progeny (except for a weak non- specific adsorption). This is illustrated in Table VII by the adsorption to H and 13/211. It should be noted that a phage progeny grown from S''-labeled phage and containing a larger or smaller amount of contaminating radioactivity could not be distinguished by any known method from authentic S36-labeled phage,