-4- 
3) Eukaryotic DNA - In the low risk category are most experiments! 
involving the fusion of prokaryotic vectors with DNA from prokaryotes, lower 
eukaryotes, plants, invertebrates and cold— olooded vertebrates. Jvioderate 
risk experiments involve the joining of DNA of warm-blooded vertebrates to 
prokaryotic vectors or the construction of recombinants between animal 
vectors and any DNA. Experiments with a nigh risk include the fusion o» 
eukaryotic or prokaryotic genes to prokaryotic vectors when the resultant 
organism is likely to express a toxic or a pharmacologically active agent. 
4. Implementation 
It is clear that in many countries steps are already being taken by 
national bodies to formulate and establish guidelines. Until such guidelines 
are established we urge individual scientists to use the present document 
as a guide. There are in addition some recommendations which need not 
wait until that time and which the scientific community could implement 
directly. 
A. Development of Vectors and Hosts. 
i 
One of the most important and interesting accomplishments of 
the meeting was the beginning of the design and construction of bacteria and 
vectors which could radically improve the safety of these procedures by 
many orders of magnitude. It is certain that in the near future there will 
become available special variants of X phage, non-transmis sible plasmids 
and special E. coli which will not only optimize safety but will also bring 
about considerable technical improvements in the methods themselves. Other 
bacterial systems, particularly suitably modified strains of B. subtilis , may 
also be specially useful for particular purposes. There is also the possibility 
that a suitable vector may be found for simple eukaryotic cells. We think 
that work which aims to improve the vectors or hosts should be given high 
priority. 
B. Laboratory Procedures 
I 
Before any experiments of this kind are initiated, the research 
staff of the laboratory shall be informed of all of the hazards that might be 
associated with such experiments. Laboratory workers must also be trained 
in the containment procedures that are designed to control the hazards. This 
training must include emergency procedures that are to be performed in the 
event of an accident. It is also strongly recommended that appropriate health 
surveillance of all personnel, including serological monitoring, be conducted 
periodically to establish a base for epidemiological analyses. 
C. Education 
A continuing reassessment of these problems to take into 
account and developing scientific knowledge is essential. This could be 
achieved by a series of annual courses, workshops and meetings which 
would also serve to train individuals in the relevant methods. Consideration 
should also be given to the establishment of a newsletter for the rapid 
dissemination of new information pertinent to the effectiveness of biological 
containment. 
