the ( diversity of sHtlbonUi in Binninghlltn / university station / BIRMINGHAM. Alabama 35294 
the Medical Center /department of microbiology / October 4, 1979 
Dr. Donald Fredrickson 
Di rector 
National Institutes of Health 
Bethesda, Maryland 20014 
Dear Don: 
I am opposed to the change in the NIH Guidelines for Recombinant DNA Research 
recently recommended to you by the Recombinant DNA Advisory Committee to exempt 
all recombinant DNA experiments using Escherichia coli K-12 hosts (not 
containing conjugative plasmids or lysogenic for generalized transducing phages) 
with lambda or lambdoid bacteriophage and nonconjugative plasmid vectors. 
My reasons are as follows: 
First, much of the data on the safety of the £. col i K-12 systems pertains to the 
genetically disabled EK2 systems and such data, whether on survival or transmissi- 
bility, are irrelevant in justifying the exemption proposed since wild-type £. col i 
K-12 hosts with wild-type nonconjugative plasmid and wild-type lambda phage 
vectors would be permissible to use. 
Second, data on the safety of the various E,. col i K-12 host-vector systems as 
were presented and discussed at the Falmouth meeting in 1977 were already evalu- 
ated by the membership of a previous Recombinant DNA Advisory Committee and were 
used to justify lowering the levels of containment required for many experiments 
as permitted by the revised NIH Guidelines for Recombinant DNA Research as issued 
on January 2, 1979. One can thus ask what is the basis for the current committee's 
recommendation to use these same data to justify an additional lowering of con- 
tainment? 
Third, essentially all data obtained since 1977 by NIH contractors conducting 
risk assessment experiments to evaluate the safety of the £. col i K-12 systems 
have indicated that host strains and bacteriophage lambda vectors survive better 
in many environments than previously believed (see Recombinant DNA Technical 
Bulletin, Volume 2, No. 2, July, 1979). As a consequence, transmission of recombi- 
nant DNA from K-12 to other microbes is a more probable event than was previously 
believed (see pages 3-4 from my letter of May 11, 1979 to William Gartland). 
Fourth, although the polyoma risk assessment experiments provided data to 
indicate that viral genetic information was more safely studied when in E_. col i 
than when in the intact virus, they also indicated that a new pathogenic agent. 
[339] 
AN AFFIRMATIVE ACTION I EQUAL OPPORTUNITY EMPLOYER 
