INDEPENDENT FUNCTIONS OF VIRAL PROTEIN AND NUCLEIC 

 ACID IN GROWTH OF BACTERIOPHAGE* 



By a. D. HERSHEY and MARTHA CHASE 



{From the Department of Genetics, Carnegie Institution of Washington, Cold Spring 



Harbor, Long Island) 



(Received for publication, April 9, 1952) 



The work of Doermann (1948), Doermann and Dissosway (1949), and 

 Anderson and Doermann (1952) has shown that bacteriophages T2, T3, and 

 T4 multiply in the bacterial cell in a non-infective form. The same is true of 

 the phage carried by certain lysogenic bacteria (Lwoff and Gutmann, 1950). 

 Little else is known about the vegetative phase of these viruses. The experi- 

 ments reported in this paper show that one of the first steps in the growth of 

 T2 is the release from its protein coat of the nucleic acid of the virus particle, 

 after which the bulk of the sulfur-containing protein has no further function. 



Materials and Methods. — Phage T2 means in this paper the variety called T2H 

 (Hershey, 1946); T2// means one of the host range mutants of T2; UV-phage means 

 phage irradiated with ultraviolet light from a germicidal lamp (General Electric 

 Co.) to a fractional survival of 10~^. 



Sensitive bacteria means a strain (H) of Escherichia coli sensitive to T2 and its 

 h mutant; resistant bacteria B/2 means a strain resistant to T2 but sensitive to its 

 h mutant; resistant bacteria B/2/; means a strain resistant to both. These bacteria 

 do not adsorb the phages to which they are resistant. 



"Salt-poor" broth contains per liter 10 gm. bacto-peptone, 1 gm. glucose, and 1 

 gm. NaCl. "Broth" contains, in addition, 3 gm. bacto-beef extract and 4 gm. NaCl. 



Glyceroldactate medium contains per liter 70 mM sodium lactate, 4 gm. glycerol, 

 5 gm. NaCl, 2 gm. KCl, 1 gm. NH4CI, 1 mM MgCl2, 0.1 mM CaCl2, 0.01 gm. gelatin, 

 10 mg. P (as orthophosphate), and 10 mg. S (as MgS04), at pH 7.0. 



Adsorption medium contains per liter 4 gm. NaCl, 5 gm. K2SO4, 1.5 gm. KH2PO4, 

 3.0 gm. Na2HP04, 1 mM MgS04, 0.1 mM CaCU, and 0.01 gm. gelatin, at pH 7.0. 



Veronal buffer contains per liter 1 gm. sodium diethylbarbiturate, 3 mM MgS04, 

 and 1 gm. gelatin, at pH 8.0. 



The HCN referred to in this paper consists of molar sodium cyanide solution 

 neutralized when needed with phosphoric acid. 



* This investigation was supported in part by a research grant from the National 

 Microbiological Institute of the National Institutes of Health, Public Health Service. 

 Radioactive isotopes were supplied by the Oak Ridge National Laboratory on alloca- 

 tion from the Isotopes Division, United States Atomic Energy Commission. 



Reprinted by permission of the authors and The Rockefeller 



Institute from The Journal of General Physiology, 36 (1), 



39-56, September 20, 1952. 



87 



