Page Five 
September 13, 1978 
II. Containment 
This section is very well done and a considerable 
improvement over the 1976 Guidelines. I would hope, 
however, that one of the next tasks of the RAC be to consider 
physical containment requirements for large scale and 
industrial procedures, for the reasons discussed under my 
comments on part I . 
Under section II-D-2 on the certification of the Host- 
Vector Systems, I would suggest an expansion of section II- 
D-2-b-l, specifically a requirement for a thorough discussion 
of the physiological properties of the organism, particularly 
those related to its reproduction and survival and the mech- 
anisms by which it exchanges genetic information, not simply 
the range of organisms with which it exchanges. For example, 
the ability to form spores has a direct bearing on the 
survival of an organism in nature. Data on such properties 
as whether such organisms exchange genetic material by 
"normal" transformation (e.g. B. subtilis , H. influenzae ) , 
transducing phages, conjugation, etc. and the degree to 
which each occurs in the organism's natural environment 
should also be required. 
Section II-D-1 is a bit vague on just what criteria 
will be applied to the certification of non E. coli host 
vector systems. The term "comparable in containment to 
E. coli K-12" might be a little too general, particularly 
when the putative host vector system contains properties 
not directly comparable to those of E. coli or normally 
inhabits a rather different type of environment, E, coli 
is not a spore former, for example. Therfore, a deletion 
mutation in one of the genes controlling spore formation 
would be an appropriate requirement for approval of a spore 
former as an HV-1 system. 
III. Containment Guidelines for Covered Experiments 
In general, the reductions in containment levels specified 
in this section, together with the exemptions accorded to 
clearly safe host-vector systems, appear to be entirely 
justified. There still remain some ambiguities which need 
clarification . 
Section III-A-3 uses the terms "purified" and "free of 
harmful genes" as criteria which an Institutional Biosafety 
Committee must consider in order to approve lowering containment 
[A-132] 
