Case Studies

Faster Gnotobiotic Mouse Facility Sterilization with SteraMist iHP

The University of Virginia Center for Comparative Medicine launched its gnotobiotic mouse program in 2018, housing mice in flexible film isolators maintained via CBClean® supply cylinders and flexible film transfer tunnels. As a germ-free mouse isolator decontamination process, sterility is non-negotiable — any contamination event can compromise an entire study and set back months of research.

Initially, the facility relied on compressed air atomizers for flexible film isolator sterilization, a process that required several hours of chemical exposure to achieve confirmed sterility. For a program built on germ-free husbandry, that turnaround time was a significant operational bottleneck — slowing the pace of research and limiting the throughput of the entire gnotobiotic mouse facility.

“We find that the SteraMist method of achieving sterility is equivalent to other methods that have been reported in the literature, but significantly saves time without compromise of sterility.” — Director, UVA Center for Comparative Medicine

The Challenge: How to Sterilize Flexible Film Isolators Faster:

Research teams operating gnotobiotic mouse facilities face a persistent question: how do you sterilize flexible film isolators faster without sacrificing validated sterility? Traditional vaporized hydrogen peroxide isolator decontamination and compressed air atomizer approaches can achieve the required sterility levels, but their lengthy exposure cycles create bottlenecks that slow germ-free husbandry workflows and reduce research capacity.

The UVA team needed a hydrogen peroxide laboratory decontamination solution that could match the sterility assurance of legacy methods while dramatically cutting cycle times — without introducing risk to the germ-free status of their mouse colonies.

The facility had previously encountered SteraMist technology during routine maintenance of their BSL-3 facility, where BSL-3 facility rapid decontamination demands are among the most rigorous in research settings. That firsthand experience with iHP performance gave them the confidence to evaluate it for their gnotobiotic program.

The Solution: SteraMist iHP Hydrogen Peroxide Fogging for Germ-Free Mice

The UVA Center for Comparative Medicine acquired their own SteraMist unit to assess its practical application for hydrogen peroxide fogging validation in germ-free mice housing — specifically for germ-free mouse isolator decontamination of flexible film housings and transfer tunnels during routine husbandry cycles.

Unlike conventional vaporized hydrogen peroxide isolator decontamination systems, SteraMist’s ionized Hydrogen Peroxide (iHP) technology generates a fine, ionized mist that penetrates flexible film surfaces and reaches the interior geometry of isolators efficiently — without the extended dwell times required by traditional hydrogen peroxide vapor approaches.

The Result: Validated Sterility in 15 Minutes

The outcome of this SteraMist gnotobiotic mouse program case study was clear and measurable. SteraMist iHP® successfully achieved full sterility within 15 minutes when applied from a distance of 16 inches — compared to the several-hour cycles previously required.

Hydrogen peroxide fogging validation for germ-free mice was conducted using 10⁶ Geobacillus stearothermophilus biological indicator discs — the industry benchmark for sterilization confirmation. Following a three-day incubation period, the discs showed no growth, confirming that SteraMist’s ionized hydrogen peroxide laboratory decontamination had achieved full sporicidal sterility.

Key outcomes of this gnotobiotic mouse facility sterilization case study include:

• 15-minute cycle time for complete flexible film isolator sterilization, versus several hours with compressed air atomizer methods
• Validated sterility confirmed via Geobacillus stearothermophilus biological indicator challenge at 10⁶ CFU
• No compromise to germ-free status of the mouse colony
• Equivalent efficacy to other methods reported in peer-reviewed literature, per the facility director
• Scalable adoption — UVA purchased a second SteraMist unit following the validated results

For gnotobiotic mouse facility sterilization teams evaluating alternatives to legacy vaporized hydrogen peroxide isolator decontamination systems, SteraMist iHP delivers the sterility assurance required for germ-free research — in a fraction of the time.