2 
were conservative, prohibiting all experiments with known risks. 
Where risks were unknown but potentially significant, appropriate 
standards were set to minimize those risks. Many recombinant DM 
experiments have been conducted throughout the world during the past 
five years and are continuing. To date, no known hazardous organism 
has been produced in this work, and the risk of converting harmless 
organisms to harmful ones by recombinant DM experiments remains 
speculative. Further work will eventually determine the limits of 
these speculative risks. 
Scientific Developments 
There is new scientific information developed over the past year 
that lessens concern over the possible environmental hazard from the 
research conducted under the NIH Guidelines. Dr. Roy Curtiss III, 
Professor of Microbiology at the University of Alabama School of 
Medicine in Birmingham, and others have demonstrated that biological 
containment measures — methods developed to weaken bacteria used in 
the experiments — would prevent these bacteria from surviving in a 
natural environment if they were t<? escape from the laboratory. 
At a scientific conference held this past spring in Falmouth, 
Massachusetts, further evidence was given that the insertion of 
recombinant DNA into E. coli K-12 (the principal organism used in these 
experiments) could not transform it into a dangerous agent. Thus, risks 
from this cause appear minimal, either for laboratory personnel or the 
public at large. Dr. Sherwood Gorbach, chairman of the conference, 
[ 879 ] 
