THE UNIVERSITY OF CHICAGO 
DEPARTMENT OF BIOPHYSICS AND THEORETICAL BIOLOGY 
CUMMINGS LIFE SCIENCE CENTER 
920 BAST 5 8 T H STR EBT 
CHICAGO • ILLINOIS 60637 
December 11, 1979 
Dr. Donald Fredrickson 
Director 
National Institutes of Health 
Bethesda, Maryland 
Dear Dr. Fredrickson, 
I support the proposed revised guidelines for recombinant 
DNA research, including the P1/EK1 recommendation. The importance 
of recombinant DNA research to the understanding of gene 
structure and function is now quite apparent, and such research 
should be performed at reasonable levels of containment. 
I feel that the increased knowledge of the safety of experiments 
using E. coli K12 hosts is sufficient to support the proposed 
changes . 
Sincerely 
[ 445 ] 
