33062 
NOTICES 
tion. It Is based on a reassessment 
made by these experts In the field of 
virology of the potential hazards of In- 
serting pieces of viral DNA into E. 
coit I believe the argument presented 
in the "Ascot" report and the working 
group report are well founded, specifi- 
cally that “the probability that K-12 
organisms carrying viral DNA Inserts 
could represent a significant hazard to 
the community was so small as to be 
of no practical consequence • • • viral 
genomes or fragments thereof, cloned 
In E. coil K-12 using approved plasmid 
or phage vectors pose no more risk 
than work with the infectious virus or 
its nucleic acid and in most, if not all. 
cases clearly present less risk." Accord- 
ingly. section UI-A-2-a of the PRG- 
N1H has been completely rewritten. 
Section IIl-A-2-b. Eukaryotic Organ- 
elle DNA into E. colx K-12 
To be consistent with the one step 
lowering of physical containment de- 
scribed earlier for shotgun experi- 
ments with primate DNA. the levels 
for mitochondrial DNA from primates 
has been similarly lowered by one step 
In physical containment In the PRG- 
NIH as compared to the PRG-RAC. 
Section II I- A- 3. Loicering of contain- 
ment for characterized or purified 
DNA preparations and clones 
Concern was expressed by several 
commentators regard. ng the revisions 
In the PRG-RAC which would allow 
the local IBC (with notification to be 
sent to NIH) to reduce either the bio- 
logical or physical containment level 
by one step if (1) the DNA is W- per- 
cent purified and shown to be free of 
harmful genes prior to its insertion 
into a recombinant molecule, or (2) if 
subsequent to Insertion the clone is 
rigorously characterized and shown to 
be free of harmful genes. In the origi- 
nal guidelines lowering in case (2) 
could only be done with NIH prior ap- 
proval. 
There was support from several com- 
mentators for the changes in th«s sub- 
section. The rationale is explained in 
new language inserted into this section 
of the PRG-RAC. which is retained in 
the PRG-NIH; Le.: 
Mar.)- of the risks which might conceiv- 
ably arise from some types of recombinant 
DNA experiments, particularly shotgun ex- 
periments. would result from the inadver- 
tent cloning of a harmful sequence. There- 
fore. In cases where the risk or inadvertent- 
ly cloning the wrong DNA is reduced by 
prior enrichment for the desire piece, or in 
which a done, made from a random assort- 
ment of DNAs. has been purified and the 
absence of harmful sequences established, 
the containment conditions for further 
work may be reduced. 
Some commentators noted the ambi- 
guity and difficulty attendant in the 
phrase free of harmful genes." The 
EMBO Standing Advisory Committee 
on Recombinant DNA Research re- 
ports that "several national guidelines 
for recombinant DNA research state 
that containment measures may be re- 
laxed once a cloned DNA fragment 
has been biochemically characterized 
and shown to be free of harmful genes 
(NIH guidelines) or devoid of any 
known pathogenic characteristic 
(French guidelines). The EMBO com- 
mittee believes the latter to be a more 
feasible requirement, but neither can 
readily be met. and the committee 
finds it difficult to suggest what sorts 
of experimental tests might be devised 
to meet these requirements." 
I agree that the terms character- 
ized' and free of harmful genes' are 
unavoidably vague." However, foot- 
note 3 of the PRG-NIH goes on to list 
five types of data which should be con- 
sidered In making this determination. 
Some commentators were also con- 
cerned that this grant of additional 
authority to the local IBC’s for single 
step lowering in containment levels 
might introduce variability in the ap- 
plication of the guidelines. I have con- 
sidered this pcsnblity and have decid- 
ed that the principle of promoting 
local Involvement in the implementa- 
tion of the guidelines outweighs the 
difficulties which may be eoncoun- 
tered in this process. In an attempt to 
minimize these problems. I have ( 1 ) at- 
tempted to make all parts of the 
guidelines as clear, specific, and unam- 
biguous as possible, and (2> expanded 
the "Roles and Responsibilities" 
secton to outline functions and respon- 
sibilities in greater detail. Also, the 
guidelines require that the Office of 
Recombinant DNA Activities at the 
NIH be notified in writing of such an 
action. A mechanism is therefore in 
place to ensure that such actions pro- 
ceed with an acceptable degree of uni- 
formity. 
The question was raised whether a 
clone, the containment level of which 
was lowered by the IBC at Institution 
X. may after shipment to Institution 
Y still be used at the lower level with- 
out review by the IBC at Institution 
Y. It clearly has been, and remains, 
the intention of both the RAC and 
myself that the IBC at the receiving 
institution must approve the reducton 
in containment for the hanging of the 
clone in such a situation. The investi- 
gator at the receiving institution must 
handle the clone at the higher level 
until such permission is granted. 
One commentator urged that prior 
cloning be accepted as a technique for 
the purification of DNA molecules 
prior to their reinsertion in a new re- 
combinant DNA molecule. The PRG- 
RAC specified that purification must 
be achieved "by physical or chemical 
techniques." The criterion for the 
single step reduction in containment 
levels in this situation is that the DNA 
preparation be S9 percent pure; I see 
no reason to so restrict the means by 
which such purification is attained. I 
have accepted this suggestion as a 
means of better serving the needs of 
the investigator without reducing the 
margin of safety to the public and the 
environment, and therefore have 
stricken from the PRG-NIH the words 
"by physical and chemical techniques ” 
following the worked "purified." 
One commentator noted that the 
PRG-NIH might be nterpreted as al- 
lowing a single step reduction in con- 
tain: ent levels for purification of the 
DNA prior to Us insertion into a re- 
combinant DNA molecule, and then a 
subsequent further single step reduc- 
tion in containment level once the 
same molecule was cloned. This was 
not intended. Therefore, clarifying 
language has been added in the PRG- 
NIH stating that an IBC may give ap- 
proval for a single step reduction in 
physical or biological containment on 
receipt of evidence of characterization 
of a clone derived from a shotgun ex- 
periment and its * * 
Finally, as noted above in this docu- 
ment under "8ectlon HI-Al-a — Shot- 
gun Experiments into E. coil K-12 
With Inserted Eukaryotic DNA." the 
RAC recommended at its April 27-28. 
1978. meeting (and I have accepted the 
recommendation and inserted it in the 
PRG-NIH). that the containment 
levels for shotgun of primate DNA 
into E. coil K-12 be lowered to 
P2~EK2. However, on the recommen- 
dation of the RAC. a stipulation added 
in section III-A-l-a of the PRG-NIH 
is that for primate shotgun "any low- 
ering of containment below these 
levels (Le.. for purified DNA or charac- 
terized clones) cannot be made solely 
by an institutional biosafety commit- 
tee but requires NIH approval." Lan- 
guage stating this limitation in au- 
thority of the IBC with regard to pri- 
mate DNA has been inserted into sub- 
section III-A-3 of the PRG-NIH. as 
has language indicating that any low- 
ering of containment under this sec- 
tion to levels below PI - EX1 requires 
prior NIH approval. 
Section Ill-E. Experiments with Other 
Prokaryotic Host-Vectors 
Some commentators felt that the 
PRG-RAC unnecessarily emphasized 
the use of E. coil K-12 and would not 
allow important recombinant DNA ex- 
periments to be done in other prokar- 
yotic hosts. Section III-B describes the 
use of prokaryotic host-vector systems 
other than E. coli K-12 which have 
been approved as HYI hosts. It should 
be remembered that “self-cloning ex- 
periments with prokaryotic hosts are 
exempt from the guidelines under ex- 
emptions I-E-2 and I-E-3 and that 
other experiments involving DNA seg- 
ments from species that exchange 
FtDClAl tEttSTE*. VOL 43. NO. 144 — ftlDAY. AX.T 21. 1971 
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