The. Joseph and Rose Kennedy 
Georgetown University 
Institute of Ethics 
Washington, D.C. 20057 
202/625-2371 
September 1, 1978 
Dr. Donald S. Frederickson 
Director 
National Institutes of Health 
Building One 
Bethesda, Maryland 20014 
Dear Dr. Frederickson: 
I am writing in response to your request for comments on the most 
recent revision of the NIH Guidelines for Recombinant DNA Research 
[Federal Register 43 (146): 33042-33178, 28 July 1978]. 
Several researchers have recently indicated their interest in 
developing alternative host-vector systems to E_^ coli K-12. Among 
the proposed systems are the following: 
Bacillus subtilis 
Yeast 
Neurospora 
Salmonella 
Pseudomonas . 
Under the proposed revised guidelines published on July 28, 1978, 
self-cloning experiments involving any of these hosts would be exempted. 
However, prior to any use of these organisms as host-vector systems, 
they would, according to the current revision, need to be certified as 
HV-1 systems. 
The current requirements for HV-1 systems are (1) low levels of 
survival of the vector in its host outside the laboratory and (2) low 
levels of transmission of the vector from the propagation host to other 
[A— 7 5] 
