52 BACTERIOPHAGES 



manner for the isolation of nucleic acid from T2 (Mayers and 

 Spizizen, 1954). 



Bacteria are generally more sensitive to detergents than are 

 bacteriophages, suggesting the use of detergents to rid ph age- 

 containing materials of bacteria (Kalter, Mordaunt, and Chap- 

 man, 1946). Detergents presumably act by denaturing proteins 

 and cell membranes. Their properties are summarized in a 

 symposium (Anson, 1946). 



4. Chelating Agents 



Chelating agents are chemicals that form undissociated 

 complexes with metal ions. Lark and Adams (1953) found that 

 citrate, ethylenediaminetetraacetate and -triphosphate ac- 

 celerated the inactivation of phage T5 at low salt concentrations. 

 These substances may act by forming a complex with some 

 cation bound to the phage particle. Stocks of phage T5 are 

 heterogeneous with respect to susceptibility to the action of 

 chelating agents, since inactivation curves are not exponential 

 with respect to time. 



5. Mustard Gas 



Mustard gas and nitrogen mustard are of biological interest 

 not only because they inactivate enzymes and kill viruses and 

 microorganisms but also because of their mutagenic activity. 

 Mustard gas was tested on a variety of microorganisms, viruses, 

 enzymes, and on the pneumococcus transforming principle by 

 Herriott (1948). Among the test objects were coliphage T2 and 

 a staphylococcus phage. The phages were inactivated in ac- 

 cordance with first-order kinetics, the velocity constants being 

 of the same order of magnitude as those found for microorganisms 

 but larger than those for enzymes. Luria and Dulbecco (1949) 

 reported that nitrogen mustard inactivated T2 and T6. An 

 analysis of the effect of mustards on phages might help to eluci- 

 date the nature of the so-called radiomimetic action of mustards. 

 Herriott and Price (1948) found that mustard -killed bacterial 



