During the past year, considerable interest has developed regarding 
the potential benefits and biohazards associated with the production of 
recombinant DNA molecules and their subsequent amplification in both 
prokaryotic and eukaryotic cells. 
Many individuals have felt that an experiment involving the cloning 
of polyoma DNA in _E. colt , using either a lambdaphage or plasmid vector, 
and the subsequent inoculation of mice with the resultant bacterial 
cultures, would be highly informative. We have been charged by the 
N.I.H. Advisory Committee on Recombinant DNA to plan and carry out such 
experiments utilizing facilities of suitable containment that are available 
to N.I.H. intramural scientists in Bethesda. It should be noted that 
these experiments are being done on the basis of an exemption from the 
San Diego guidelines voted by the N.I.H. Advisory Committee. 
The reasons for selecting polyoma virus for such an experiment are 
manifold. Polyoma virus DNA Is small (3 x 10^ daltons), is well char- 
acterized chemically and physically, and is infectious; the virus appears 
to represent no biohazard to man. However, the chief reason for its 
selection is the well-documented observation that parenteral Inoculation 
of mice with minimal doses of virus regularly leads to an immune response 
(Rowe et al. , Journal of Experimental Medicine, 109 , 379, 1959; Rowe et 
al. , Perspectives in Virology, ,2, 177, 1961). This phenomenon is the 
basis for the mouse antibody production (MAP) test for polyoma virus. 
In this assay, mice from a polyoma-free colony are injected with test 
material and, three to four weeks later, are tested for serum hemagglutination 
inhibiting (HI) antibody against the virus. This test can detect approxi- 
mately one tissue culture infectious dose (TCID) of polyoma virusj 
adults are as sensitive as suckling mice. Feeding and intranasal instillation 
of virus are much less efficient modes of infection. We thus view the 
[Appendix C — 78] 
