43 
those called for in the guidelines without peer review (see Section IV. B). 
In the event of a question as to what containment conditions should 
apply, the Recombinant DNA Molecule Program Advisory Committee may be 
petitioned for a reevaluation of the level of containment required. 
The institution of appropriate safeguards includes a continuing 
control on containment procedures, on the effective operation of the 
physical containment facilities, and on those aspects of the genotype 
of the host-vectors that are relevant to the biological containment 
they provide. Although the data on the phenotypic characteristics of 
a giver host-vector that determine its level of biological containment 
usually will have been obtained in other laboratories, the principal 
investigator has the responsibility for being able to justify the overall 
containment determination on the basis of such data. That is, it is not 
sufficient that he or she simply be assured by some other person of the 
determinatio r of the containment level; rather investigators should be 
or become sufficiently knowledgeable to make their own determination. 
In addition, investigators have the responsibility of ascertaining that 
the hosts and/or vectors exhibit the required genotype prior to their 
use in experiments with DNA recombinants in their laboratories. Such 
ascertainment generally involves a simple phenotypic test for each 
relevant mutation. 
B. Institutional role - Implementation starts with the principal in- 
vestigator's evaluation of the potential biohazards associated with a given 
project and of the appropriate safeguards to be applied. To help in this 
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