How can you sterilize a mouse? - briefly
Apply a validated autoclave cycle (121 °C, 15 psi, 15 min) or a calibrated gamma‑irradiation dose (≈25 kGy) to achieve complete sterility; chemical disinfectants such as 70 % ethanol do not provide true sterilization. Ensure the method is approved by institutional biosafety guidelines and that the mouse is confirmed sterile by appropriate microbiological testing.
How can you sterilize a mouse? - in detail
Sterilizing a laboratory mouse requires a method that eliminates all microorganisms without compromising the animal’s physiological integrity. The most reliable approaches are:
- Autoclaving (steam sterilization). Place the mouse in a sealed, heat‑resistant container that can withstand 121 °C at 15 psi for 15 minutes. Verify that the container prevents water ingress and maintains a sterile environment after the cycle. Allow the animal to cool gradually to avoid thermal shock.
- Gamma irradiation. Expose the mouse to a dose of 25–30 kGy using a calibrated source. This dose destroys bacterial spores, viruses, and fungi while preserving tissue structures. Follow with a 24‑hour observation period to assess acute effects.
- Chemical sterilants. Immerse the mouse in a sterile solution of 70 % ethanol for 5 minutes, then rinse in sterile saline. For deeper penetration, a brief exposure (2 minutes) to 0.5 % glutaraldehyde can be employed, followed by extensive saline washes to remove residual toxin.
- Dry heat. Place the mouse in a sterile metal chamber at 160 °C for 2 hours. This method is suitable for short‑term sterilization when moisture‑based techniques are impractical.
Preparation steps common to all methods
- Confirm the animal’s health status; only healthy subjects should undergo sterilization.
- Fast the mouse for 4 hours to reduce gastrointestinal content that could interfere with heat or chemical penetration.
- Use aseptic technique: wear sterile gloves, work in a biosafety cabinet, and sterilize all tools before contact.
Post‑procedure verification
- Perform culture tests on swabs taken from the fur, oral cavity, and rectum 24 hours after treatment.
- Conduct PCR assays for common pathogens (e.g., Mycoplasma spp., murine cytomegalovirus) to ensure complete decontamination.
- Monitor vital signs (temperature, respiration, activity) for at least 48 hours to detect adverse reactions.
Safety considerations
- Autoclave and dry‑heat procedures require pressure‑rated equipment and proper venting to prevent explosions.
- Gamma irradiation demands shielding and dosimetry checks to protect personnel.
- Chemical agents must be handled in a fume hood; residues can cause tissue irritation if not thoroughly removed.
By selecting the appropriate technique, following strict preparation protocols, and confirming sterility through microbiological testing, a mouse can be rendered free of contaminants while maintaining its suitability for experimental use.