11 
■Cultures of viable organisms containing recombinant mole- 
cules shall be handled in a closed system (e.g., closed vessels 
used for the propagation and growth of cultures) or other primary 
containment equipment (e.g.. Class III biological safety cabinet 
containing a centrifuge used to process culture fluids) which is 
designed to prevent the escape of viable organisms. Volumes less 
than 10 liters may be handled outside of a closed system providing all 
physical containment requirements specified in Section II-B-3 of the 
Guidelines are met." 
Dr. Waitz suggested this language is ambiguous. He suggested the language be 
modified to read in part: 
"Cultures of viable organisms containing recombinant ENA molecules 
shall be handled in a closed system used for the propagation, growth 
and processing of cultures, other primary containment equipment or 
other appropriate method of containment approved by the IBC which is 
designated to reduce the potential for escape of viable organisms ...." 
Er. Waitz also proposed that Section VII-B-3 be modified. Section VII-B-3 
reads: 
"VII-B-3. Sample collection from a closed system, the addition of 
materials to a closed system and the transfer of culture fluids from 
one closed system to another shall be done in a manner which prevents 
the release of aerosols or contamination of exposed surfaces." 
[401 
