450 



INACTIVATION OF BACTERIOPHAGES 



rate of inactivation of the free radioactive T2 stored at the same tempera- 

 ture. (Neither the control culture infected with non-radioactive T2 nor the 



DAYS 

 2 4 6 8 12 16 20 25 



T — T-T — I I I I I I I I I I I I I I I I Mill 



.0* 



Fig. 4. P^- inactivation of T2 (^o = 88 mc./mg.) inside infected bacteria at — 196°C. 

 Filled triangles, multiplicity of infection: 0.075 (monocomplexes) . Open triangles, 

 multiplicity of infection: 2.2 (multicomplexes). Filled circles, free T2. The dashed 

 curve indicates the expected survival of infective centers at a multiplicity of 2.2 in 

 the absence of multiplicity reactivation. 



corresponding free phage showed any significant loss of titer.) Hence P^- 

 decay occurring in the DNA after it has been separated from the protein 

 "coat" and exchanged its place in the phage head for the protoplasm of the 

 host cell is still capable of destroying the reproductive capacity of the parent 

 phage, although this inactivation now proceeds with a slightly reduced effi- 



289 



