Cold Spring Harbor Laboratory 
P.O. Box 100, Cold Spring Harbor, New York 11724 (516) 692-6660 
December 27, 1979 
Director 
National Institutes of Health 
Bethesda, MD 20205 
Dear Dr. Fredrickson: 
I am writing in support of the new N.I.H. guidelines 
for recombinant DNA research as published in the Federal 
Register of November 30, 1979. I would like to emphasize 
my approval of the proposed change to classify most 
experiments using coli K-12 host-vector systems at the 
PI level of containment. I think that the Recombinant 
Advisory Committee was correct in their recommendation of 
this proposal and that studies of the pathogenicity 
and transmission of coli as well as the risk assessment 
experiments of Drs. Rowe and Martin make the downgrading 
of E^_ coli K-12 experiments extremely sensible. 
Very truly yours 
Dr. Terri Grodzicker 
Senior Scientist 
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