Validation of an Animal Isolation Imaging Chamber for Use in Animal Biosafety Level-3 Containment.

Live imaging of animals infected with pathogenic microbes poses a contamination risk to equipment, personnel and other animals. A Caliper animal isolation chamber designed for the IVIS(®) Spectrum imaging system was tested as a containment device for mice infected with microbes assigned to animal biosafety level-3 (ABSL-3). A testing protocol was developed by adapting two published standards to test other equipment in high containment environments. The protocol included quantitative leak-testing of the high efficiency particulate air (HEPA) filters, soap bubble testing of the animal isolation chamber, and pressure decay testing of the complete containment system. HEPA filters were > 99.999% efficient (< 0.001% leakage). When attached to the Spectrum at the normal flow rate of oxygen/anesthetic mix (0.25 L/min), the chamber was positively pressurized at 0.11 inches of water (in H(2)O). No leaks were detected by soap bubble testing at flow rates of 0.25 L/min to 2.0 L/min, generating pressures up to 2.90 in H(2)O. (26-fold increase over normal operating pressure). The complete containment system passed pressure decay testing at 2.0 in H(2)O by sustaining 95% of the initial pressure over a 30 minute period.The Caliper animal isolation chamber provides appropriate isolation for the IVIS(®) Spectrum imaging system. When used as a containment device, it must undergo periodic performance testing, as described here, since it operates under positive pressure. The chamber is an appropriate component of ABSL-3 containment when combined with proper administrative controls and work practices. The testing protocol described here can be used to validate containment devices for other imaging systems or animal species.

Duke Scholars

Author Scott Alderman Medicine, Duke Human Vaccine Institute

Author Richard Frothingham Medicine, Infectious Diseases