at which the experiments were done. Dr. Jonathan A. King (MIT) 
noted that very little information has been gathered concerning 
the incidence of laboratory infection, particularly as a control 
population for future studies of laboratories involved in recombinant 
DNA experimentation. Dr. Mary-Dell Chilton (University of Washington) 
described her research on crown gall tumors in plants. The tumors 
are caused by bacterial plasmids which can also be induced to 
grow in E. coli . Under the proposed Guideliness, by one criterion 
the cloning of this plasmid DNA would be eligible for the excluded 
list of experiments but, by another, it would not. She asked that 
consideration be given to resolving this disparity. 
Other comments were made both about the lack of clear and explicit 
language in some sections of the Guidelines and about their lack 
of reference to regulation for the private sector. Dr. Ronald Cape 
(Cetus Corporation) indicated he favored passage of a law regulating 
private and public laboratories with the inclusion of exemptions 
for patent rights and trade secrets. 
Physical Containment 
Dr. Emmett Barkley (NIH) described the changes that had been made 
in the section of the Guidelines dealing with physical containment. 
He pointed out that there were no significant differences between the 
two versions except for a new format for the material and an attempt 
iv 
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