Iro S4 the rockefeller university 
^[University )£ 1230 york avenue newyork.newyork 10021 
oV , 9 oi J4 
Dr. Donald Fredrickson, Director 
National Institute of Health 
Bethesda, Md. 20014 
Dear Don, 
It was with some surprise that I heard that the subject 
of the "exemption" of recombinant DNA experiments with E. coli 
K-12 has appeared once again in the Federal Register. 
On Sept. 7, 1979 the RAC, a committee carefully put together 
so as to be highly sensitive to the public interest, voted over- 
whelmingly — sufficient to pass the SALT Treaty in the U.S. 
Senate — the resolution on E. coli K-12. 
This vote reflected the fact that all analyses, either 
experimental or theoretical, conclude that it is impossible for 
E. coli K-12 to become a pathogen by accident or even intention. 
The documentation supporting this conclusion has I know been pro- 
vided to you. 
Thus the resolution on E. coli K-12 is a sound one. Further 
delay in its implementation will only continue to waste the efforts 
of many individuals, monies and not in any way add to the public 
safety. 
December 3, 1979 
Yours sincerely 
Norton D. Zinder 
NDZ/pb 
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