THE GROWTH OF BACTERIOPHAGE 



By EMORY L. ELLIS and MAX DELBRtJCK* 



{From the William G. Kerckhof Laboratories of the Biological Sciences, California 

 Institute of Technology, Pasadena) 



(Accepted for publication, September 7, 1938) 

 INTRODUCTION 



Certain large protein molecules (viruses) possess the property of 

 multiplying within living organisms. This process, which is at once 

 so foreign to chemistry and so fundamental to biology, is exemplified 

 in the multiplication of bacteriophage in the presence of susceptible 

 bacteria. 



Bacteriophage offers a number of advantages for the study of the 

 multiplication process not available with viruses which multiply at the 

 expense of more complex hosts. It can be stored indefinitely in the 

 absence of a host without deterioration. Its concentration can be 

 determined with fair accuracy by several methods, and even the 

 individual particles can be counted by d'Herelle's method. It can be 

 concentrated, purified, and generally handled like nucleoprotein, to 

 which class of substances it apparently belongs (Schlesinger (1) and 

 Northrop (2)). The host organism is easy to culture and in some cases 

 can be grown in purely synthetic media, thus the conditions of growth 

 of the host and of the phage can be controlled and varied in a quanti- 

 tative and chemically well defined way. 



Before the main problem, which is elucidation of the multiplication 

 process, can be studied, certain information regarding the behavior of 

 phage is needed. Above all, the "natural history" of bacteriophage, 

 i.e. its growth under a well defined set of cultural conditions, is as yet 

 insufficiently known, the only extensive quantitative work being that 

 of Krueger and Northrop (3) on an a.ni[-staphylococcus phage. The 

 present work is a study of this problem, the growth of another phage 

 {a.nti-Escherichia coli phage) under a standardized set of culture 

 conditions. 



* Fellow of The Rockefeller Foundation. 



Reprinted by permission of the authors and The Rockefeller 



Institute from The Journal of General Physiology, 22 (3), 



365-384, January 20, 1939. 



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