SCHOOLS OF BASIC MEDICAL SCIENCES AND CLINICAL MEDICINE 
UNIVERSITY OF ILLINOIS COLLEGE OF MEDICINE 
190 Medical Sciences Building * 506 South Mathews * Urbana, lllinob 61801 
(217) 333-9284 
March 2U, 19dl 
Dr. Elizabeth Milewsld. 
j Bld«. 31 Rb- 
I ORDA-RIH 
Bethesda, MD 20205 
I Dear Dr. Mllevski: 
I am vrltlng in support of efforts to certify Bacillus subtilis as 
a perfectly safe bacterium and to minimize restrictions of its use as a 
cloning vehicle. I have worked with B. subtilis for seven years, following 
an equal period of working with Escherichia coli . B. stjbtilis has proved 
to be entirely harmless, and we have had little difficulty with its surviving 
when it should not (e.g., surviving autoclaving and subsequently contaminating 
I media). In fact, it dies easily (from lack of carbon/energy^ source of of 
oxygen). Its being an obligate aerobe and native to soil should make it 
especially fit as a cianing Vehicle, in comparison with E. coli , which 
. naturally inhabits intestines. The more the restrictions of its use are 
relaxed, the greater will be the tendency to shift froBi enteric bacteria 
to B. svibtilia in cloning experlsients , a desireable change. I urge you 
to remove eiU possible restrictions on its use in cloning experiments, 
and rely instead on standard (good) microbiological technique as customarily 
practiced by competent microbiologists sad biochemists, for it will provide 
protection enou^. 
Yours sincerely, 
(Jeorge W .^rdal 
Associate Professor of Biochemistry 
■ 
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