STANFORD UNIVERSITY MEDICAL CENTER 
STANFORD, CALIFORNIA 94305 
DEPARTMENT OF BIOCHEMISTRY 
Stanford University School of Medicine 
Area Code 415 
497-6161 
26 December 1979 
Dear Dr. Fredrickson 
I fully support the recent changes (Federal Register, 
Nov. 30, 1979 )in the recombinant DNA guidelines 
and strongly urge their acceptance. Sufficient 
data has been collected indicating that the original 
assesment of the risk associated with the types of 
experiments that will become EK1, PI, should the 
new guidelines be accepted, was far too high. I 
do not believe that previous guidelines were in error; 
it is preferable that all fields be well prepared for 
any experimental outcome. Having reevaluated the 
biohazard risk , it is clear that a lowering of 
containment levels is appropriate. Further consideration 
of the risks associated with the yeast vector systems 
and a lowering of the containment levels for exper- 
iments in this organism is also appropriate. 
We cannot allow scientific and technological progress 
to be hampered by unnecessary regulation. 
Thomas St. John 
[ 596 ] 
