Abstract
The biological safety cabinet is commonly employed to protect both user and product in an increasing number of biotechnology applications. It is recommended that cabinets be fully certified annually, but given the requirements of good laboratory manufacturing practices, more frequent, less disruptive user checks of equipment may be desirable. Furthermore, annual field certifications only determine that cabinets meet basic design and performance parameters and cannot reveal all issues unique to a particular cabinet. This study describes the development of a novel in-laboratory test method using common biotechnology tools that is capable of assessing bioaerosols containment as well as cabinet-specific lateral motion of bioaerosols potentially responsible for product cross-contamination. Genetically engineered viable bacteria releases, followed by colony recovery and gene amplification by polymerase chain reaction, constitute the essence of the new approach. Specifically, a nebulizer was used to release a bioaerosol within a cabinet. Single-stage bioaerosol samplers were simultaneously used to sample the challenge bioaerosol containing bacteria engineered with a plasmid conferring Kanamycin resistance. Recovered challenge bacteria were grown on media containing the antibiotic, and the presence of a DNA fragment in the bacterial plasmid was confirmed. Results demonstrated that there was detectable lateral motion of bioaerosols within the biological safety cabinet tested. The importance of such lateral motion to product cross-contamination is discussed, as are the applications for this novel testing method. It is concluded that the new technique represents an enhanced level of safety cabinet field testing ability available to the end user.