135 



PLATZMAN: Has anyone tried it? 



JONES: In the biological system? I don't think that metabolic func- 

 tions would operate sufficiently with such a change in reaction properties in- 

 duced by hydrogen replacement. 



SPIEGELMAN: Pure deuterium ? I thought they stopped when you get 

 above a certain level. 



PLATZMAN: The function of zippering would be rather different with 

 deuterium bonds, i.e. , the role of the dynamic distribution of breakages. 



CHARGAFF: I don't know anything about what a deuterium bond looks 

 like as compared with a hydrogen bond. 



PLATZMAN: It would be much weakened. It would have a completely 

 different kind of temperature effect. 



tures, 



CHARGAFF: Then you really could not expect to grow these struc- 



PLATZMAN: Well, it would be a question whether you could or not. 

 That in itself would be important. 



CHARGAFF: You would have to know whether you can grow bacteria 

 in deuterium. 



MAZIA: The Watson-Crick formulation regarding replication is ex- 

 perimentally testable independent of any concept of structural details. Stent is 

 doing it with phage and with chromosomes. 



KAMEN: What are these experiments? 



MAZIA: The principle of them is that if in the system replication 

 works, then the material of the parent molecule is distributed between the 

 daughter molecules. The experiments are essentially to determine whether the 

 parent molecule as such survives and the daughter molecules consist entirely 

 of new matter or whether the 2 daughter molecules consist of half parental mat- 

 ter and half new matter. 



CURTIS: It has to be half? 



MAZIA: Yes. 



POLLARD: It has to be done twice. You need both generations to be 



sure, 



SPIEGELMAN: That has to be checked. It really disagrees with a lot 

 of other experiments. 



POLLARD: Luria and Human also showed that multiplication by split- 

 ting takes place. We also know that it is nucleic acid synthesis which takes 

 place first. There is no intervention of proteins first. 



CARTER: What is the evidence for these things? 



POLLARD: Simply that no new protein whatsoever develops until so 



