9 
exchange genetic information with coli are classified under 
the present Guidelines at the Pi + EKl level. Under the pro- 
posed revisions this category would be eliminated because 
presumably they would go on the exempted list. If there is a 
delay in creating exemptions, however, the investigator would 
be forced to use the higher containment level in the proposed 
revisions (under the category of prokaryotes that do not 
exchange genetic information with E . coli ) . What are the 
Committee's views on placing in this section a statement to the 
effect that any experiments with prokaryotic DNA recombinants 
that do exchange genetic information with E_^ coli may be 
conducted under the containment levels of the 1976 Guidelines 
unless anu until they appear on the exempted list? 
• Since synthetic DNA will now be explicitly included in the 
Guidelines, language must be added concerning the proper 
containment levels. What are the views of the Committee on the 
following proposed language? 
" Synthetic DNAs 
"If the synthetic DNA segment carr or might yield a potenti- 
ally harmful polynucleotide or polypetide (e.g., a toxin or a 
pharmacologically disruptive agent), the containment conditions 
should be the same as would be used for propagating the natural 
DNA counterpart . 
"If the synthetic DNA sequence codes for a harmless prod- 
[ 510 ] 
