UNIVERSITY OF CALIFORNIA, SAN DIEGO 
BERKELEY • DAVIS • IRVINE • LOS ANGELES • RIVERSIDE • SAN DIEGO • SAN FRANCISCO 
SANTA BARBARA • SANTA CRUZ 
DEPARTMENT OF BIOLOGY, B-022 
LA JOLLA, CALIFORNIA 92093 
December 14, 1979 
Dr. Donald Frederickson, Director 
National Institutes of Health 
Bethesda, Maryland 20205 
Dear Dr. Frederickson: 
I am writing about the proposed change in guidelines for recombinant 
DNA experiments published on Friday, November 30 (Federal Register, Vol. 
44, p. 69218). 
In Section III-O there is a classif icatory downgrading of a large 
group of experiments in Eh coli K-12. I applaud that change. It appears 
to me to be soundly based on the accumulating experience and evaluation 
of real hazards of such experiments. Those real hazards appear now to be 
so small as not to justify the regulatory structure that has been erected 
through previous versions of the guidelines. I have confidence in the 
soundness of the advice that you have received on this subject, from the 
majority of your recombinant DNA advisory committee, to enact this revision. 
Yours truly. 
E. Peter Geiduschek 
Professor of Biology 
EPG : sb 
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