STANFORD UNIVERSITY MEDICAL CENTER 
DEPARTMENT OF GENETICS 
October 30, 1979 
Dr. Donald Frederickson 
Director 
National Institutes of Health 
Bethesda, Maryland 20014 
Dear Don: 
I have had the opportunity to read some of the comments transmitted to you 
recently by Roy Curtiss and others expressing opposition to the change in the 
NIH Guidelines for Recombinant DNA Research recommended by the Recombinant DNA 
Advisory Committee. Specifically, these comments concerned the proposal to 
exempt all recombinant DNA experiments using Escherichia coli K12 hosts (not 
containing conjugative plasmids or lysogenic for generalized transducing phages) 
with lambda or lambdoid bacteriophage and nonconjugative plasmid vectors. 
In contrast to Roy, I strongly support the proposed change in the Guide- 
lines. Roy's opposition to the change seems based on the premise that the pro- 
posed exemption for cloning in E. coli K12 is equivalent to the abolition of 
all safety measures in such work. In fact, what is being proposed by the Advisory 
Committee is reliance on standard operating procedures rather than on a cumbersome 
and costly administrative apparatus to ensure biosafety for work in this area. 
Certainly there is no indication that cloning of DNA in E^. coli K12 poses any 
hazard that warrants extraordinary precaution, and in fact, experience thus far 
indicates that recombinant DNA methods provide increased safety for work with 
genetic material that does encode hazardous products. Since there is no evidence 
of special hazard in the experiments proposed for exemption, there would seem to 
be no need for a special administrative process to promote safety; standard micro- 
biological practices appear to be adequate for work with a variety of organisms 
that are capable of causing serious disease or environmental damage; if special 
regulations or enforced guidelines are not necessary to protect the public health 
and the environment from organisms that are known to be hazardous, they surely 
should not be necessary to deal with organisms that give no indication of being 
hazardous at all. The continuation of special procedures for work involving 
cloning of DNA in JE. coli K12 would be justified only if there were some valid 
basis for believing there are special hazards. 
I strongly urge you to approve the change recommended by the Recombinant DNA 
Advisory Committee. This change would place the biohazard issues in appropriate 
perspective for a major segment of recombinant DNA work by relying on standard 
microbiological practices, rather than on special regulations, to promote biosafety. 
’ yours , 
Cohen 
Professor 
SNC:ps 
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DEPARTMENT OF CENETICS, STANFORD UNIVERSITY SCHOOL OF MEDICINE, STANFORD, CALIFORNIA 94305 • (415) 497-5052 
