Yale University 
Box 793 7 Yale Station, New Haten, Connecticut 06520 
DEPARTMENT OF MOLECULAR BIOPHYSICS 
AND BIOCHEMISTRY 
(203) 436-3611 
February 13, 1976 
Dr. Donald S. Fredrickson 
Director 
National Institutes of Health 
Bethesda, Maryland 20014 
Dear Dr . Fredrickson : 
I have just completed reviewing the Proposed Guidelines for 
Research Involving Recombinant DNA Molecules. As co-author of the 
original letter (Science 181 , 1114 (1973)) which started to focus 
attention on the possible hazards of recombinant DNA molecules, 
and which led to the formation of the Berg committee, I feel that 
the proposed guidelines are well considered and provide adequate 
precautions for future research. I urge you to adopt them. 
Yours sincerely. 
Dieter Sttll 
Associate Professor 
Molecular Biophysics 
DS:ml 
Enel . 
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