With reference to item //I290, we wish to commend the working 
groups that drafted the proposed additions to the NIH 
Guidelines. The task was prodigious but the product is 
excellent. Adoption of the additions will mark genuine 
progress in governmental oversight of re conk inant ENA 
experiments applied to plants, animals, and their associated 
microorganisms . The proposed approach is typical of that of 
NIH and the RAC historically: timely, coherent, progressive, 
and scientifically sound. 
Our specific comments are as follows: 
1. paragraph 50. "Recognition as to" should be replaced with 
' tte termination of 8 * * 11 . 
2. paragraph 58. After the phrase, ". . . cannot interbreed 
with noxious weeds. . .", we recommend the addition of the 
phrase "in the area of the experiment." There are examples 
of common plant species found in the U.S. that can 
interbreed with rare foreign species but not with any 
domestic weed. An example is tobacco, which can interbreed 
with a weed found only in Asia Minor; clearly, tobacco 
should not be moved to a higher level of containment for 
this reason. 
3. paragraph 60. Same change as in 2, above. 
4. paragraph 81. Substitute "degrees of containment" for 
"levels of biosafety." The intention is to keep levels of 
biosafety high during any experiment ; different degrees of 
containment may be required , however , to achieve this for 
different situations . 
5. paragraph 91c. A biohazard sign should not be required for 
BL1. By definition, significant hazard of experiments 
performed at this level is unlikely. The presence of the 
signs conveys an inaccurate message to passersby, and the 
impact of the warning sign is "cheapened" with respect to 
those situations for which it is appropriate. 
6. paragraph 101. Flying insects and nematodes are 
incorrectly referred to as microorganisms. 
7. paragraph 133a. We suggest that the required efficiency of 
the filters be changed to "at least 80%" if the intent is 
to establish a minimum efficiency. 
8. paragraphs 196 , 206 , 236, and 278. The requirement for 
marker sequences assumes that such sequences can 
successfully be introduced in all instances. We believe 
that the state-of-the-art of producing transgenic animals 
does not permit such assurance; we suggest inserting the 
qualifier ,l where practicable," after "In addition, . . ." 
Recombinant DNA Research, Volume 13 
[ 352 ] 
