ROCHE INSTITUTE OF MOLECULAR BIOLOGY 
MUTLC.V, NEW Jt«SEr 07110 
October 13, 1977 
Dr. Donald S. Frederickson 
Director 
National Institutes of Health 
9000 Rockville Pike 
Sethesda, Md. 20014 
Dear Dr. Frederickson: 
I an writing in response to your request for comments on the proposed 
revised Guidelines for Recombinant DNA research, published in the Federal 
Register, volume 42, number 187, September 27, 1977. 
Since I have been involved in Recombinant DNA issues in various 
capacities for some time, I have followed the recent develooments in this 
area with considerable interest. Especially noteworthy has been the 
growing consensus, based on accumulated experience and risk-assessment 
experiments, that Recombinant DNA research utilizing Z. coli K-12 based 
systems poses no significant risk to the public health and environment. This 
consensus deserves emphasis because it was in fact, concern for the oub lie 
welfare that seemed to distinguish this area from other tyoes of biomedical 
research, and was the major justification for the establishment of soecial 
guidelines. It appears that the NIH Guidelines' reliance on the E. coli 
K-12 based-systems was well founded, and biological containment will work 
even better than some of us had exoected. 
It is, of course, essential that the revised Guidelines reflect changes 
in the state of our knowledge concerning the efficacy of various containment 
procedures and conditions. Many of the revisions, including most of the 
"containment guidelines for permissible experiments" do seem to reflect these 
changes. However, in a few instances, there are inconsistencies and it is 
two such instances that X address below: 
1. The experimental Guidelines for "viruses of plants" (page 49602) 
specify P2 + EK2 £r P3 + EK1. Since the two types of containment are com- 
plementary, the flexibility provided by balancing changes in physical contain- 
ment with changes in biological containment is certainly reasonable. From 
the standpoint of the experimenter, such flexibility is also most desirable. 
continued 
[Appendix A — 9] 
