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Page 4 of Attachment H 
Origin of 10L Limit 
The origin of the 10L limit appears to have evolved at Asilomar during 
a period when few people conceived of performing large-scale fermentation 
with recombinant organisms. Or. Stanley Cohen (3) described the main 
factor which was 
considered, namely that 10L was probably as large a volume as could be 
conveniently handled in an experimental laboratory by conventional 
laboratory centrifuges. More recently. Or. David Baltimore (4) suggested 
that 10L was considered as a standard volume representing a "large 
amount" in a laboratory. There was a very conscious understanding that it 
excluded industrial-level activity. It was never suggested that increased 
volume of a culture of a safe organism resulted in any increased risk. 
Safety of E. coli K12 as Determined by Risk Assessment 
Recombinant ONA technology is the culmination of a number of basic 
discoveries in molecular biology during the preceding quarter century. 
During those years scientists learned that DNA was the storehouse of genetic 
information in all cells, and following the elucidation of the chemical 
structure of DNA, understood the manner in which this information was 
expressed and controlled in microorganisms. In the 1960's and early 
1970' s, methods of cutting up DNA molecules and rejoining them were 
developed, along with ways of introducing these molecules into functional 
cells. Although these discoveries led some scientists to question whether 
indiscriminate insertion of new genetic information into cells might lead 
t 
to public health and environmental risks, these same discoveries have been 
directly responsible for an exponential increase of new knowledge in 
molecular biology. 
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