APPENDIX E 
Table 4. Guidelines for use of polyoma and SV40 as vectors 
"Foreign" DNA 
Phys ica 1 
conta i nment 
Pol yoma 
SV40 
With virion production 
Non-pathogen 
P3 
P4 
If purified, cloned, harmless 
P3 
P3 
Low pathogenicity 
P4 
No virion production 
Non-pathogen 
P3 
P3 
Low pathogenicity 
P3 
- 
Appendix E — 30 
