Modernization of Salk's ABSL2 Facilities Through the Incorporation of Ventilated Caging - PROJECT SUMMARY
This is a proposal to modernize mouse Animal Biosafety Level 2 (ABSL2) facilities at the Salk Institute for
Biological Studies by replacing antiquated static cages with racks of individually ventilated cages (IVCs).
Together with proposed renovations to the ABSL2 animal holding room, this will double cage capacity and
enable operational efficiencies that reduce animal stress and improve the rigor and reproducibility of
experimental outcomes. Within Salk’s Conventional Research Animal Facility (CRAF) is an ABSL2 suite, which
includes a 220-ft2 animal holding room. This holding room is currently comprised of three small cubicles
adjoined to a common space. Each cubicle holds one double-sided shelving unit capable of accommodating up
to 112 static mouse cages, for a maximum of 336 cages in the holding room. Given the large number of labs
who utilize this space (33 of 54 Salk faculty), this facility is often at >80% capacity and labs have had to delay
studies until space becomes available. The proposed project removes the cubicles and installs high-density
Allentown NexGen MAX racks. The increased useable floorspace will accommodate 3 double-sided racks (192
cages each) and 1 single-sided rack (96 cages), doubling the capacity to 672 cages. The proposed
modernization will also improve living conditions and reduce stress experienced by the mice, thereby helping to
promote rigor and reproducibility of Salk research. Non-ventilated cages are associated with poor air quality
and require frequent cage changing, resulting in greater handling of the mice and higher levels of stress for the
animals. Because humidity levels are so high at Salk, cages often must be changed twice a week. Switching to
ventilated caging will extend the time between cage changes to 10–14 days. Further, the proposed floor plan
minimizes the need to roll racks to access mice, thereby reducing mouse exposure to noise and vibration.
Thus, a critical feature of the modernized CRAF ABSL2 suite is a reduction in non-experimental husbandry
variables that could potentially affect research results. Finally, improvements to this facility are an Institute
priority, as mouse ABSL2 work is at the center of the Institute’s future research endeavors, which include
cancer biology, neuroscience, and aging. Researchers within each of these programs use, and often develop,
cutting-edge technologies that require ABSL2 facilities to target and manipulate specific cell types within
mouse models. Salk’s long-term commitment to these research efforts and associated mouse ABSL2 work is
reflected in fundraising initiatives dedicated to conquering cancer, neuroscience, and healthy aging. In support
of these research priorities, this proposal seeks to: 1) replace static cages within the CRAF ABSL2 suite with
state-of-the-art IVC racks, 2) increase cage capacity within the ABSL2 suite to meet research demands for the
foreseeable future, and 3) enhance the rigor and reproducibility of mouse ABSL2 research by minimizing
animal stress. This vastly improved mouse ABSL2 shared resource will enable Salk researchers to continue
their ground-breaking research that has so dramatically impacted a wide range of scientific fields.
