LILLY RESEARCH LABORATORIES 
DIVISION OF ELI LILLY AND COMPANY . INDIANAPOLIS. INDIANA 46206 • TELEPHONE (317) 636-2211 
May 8, 1979 
Wallace P. Rowe, M. D. 
Chief, Laboratory of Viral Diseases 
National Institute of Allergy and 
Infectious Diseases 
Department of Health, Education, and Welfare 
National Institutes of Health 
Bethesda, Maryland 20014 
Dear Wally: 
I am enclosing a copy of some of the experimental data we have collected 
so far on the survival of E. coli (carrying recombinant plasmids 
containing insulin gene sequences) in the rodent intestinal tract. I 
would emphasize that this data is preliminary and other experiments 
are in progress, but I thought you would be interested since we had 
discussed some of it by phone. 
The data indicates that in conventional rats or mice, the strain and 
plasmid are lost very rapidly. In germ-free animals the plasmid per- 
sists somewhat longer, but is eventually lost. This preliminary data 
is in keeping with our assumption, based on previously published experi- 
ments, that E. coli Kq 2 strains will not colonize the intestinal tract, 
and offers further reassurance of the safety of this system. 
With best personal regards. 
Sincerely} “7* 
Head, Cell Biology Research 
JPB/az 
Enclosure 
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