2) To be inserted on page III-28 as item 5; and change "Handling 
of Recombinant DNA Molecules" to item 6. 
5. Synthetic DNAs- 
The containment conditions recommended for handling organisms contain- 
ing synthetic DNA molecules are those described for propagating the natural 
DNA segments they are intended to emulate. 
If the synthetic DNA sequence codes for a harmless product 
normally made in a prokaryote (one not known to exchange genetic 
information with E. coli ) a eukaryote, or their plasmids, 
viruses or organelles, may use the lowest combination of 
physical and biological containment conditions recommen- 
ded for the corresponding purified natural DNA 
segment. (Perhaps some examples here would be useful). 
If the synthetic DNA segment can or might yield a potentially 
harmful polynucleotide or polypeptide (e.g. a toxin or a pharma- 
cologically disruptive agent) the containment conditions should 
be the same as would be used for propagating the purified natural 
DNA counterpart. (Perhaps some examples here could also be in- 
cluded . ) 
If the synthetic DNA segment is not expressed as a polynucleo- 
tide or polypeptide product, or their products have no natural 
counterparts , the organisms containing the recombinant DNA mole- 
cules are exempt from consideration by these Guidelines. 
[Appendix A — 85] 
