The XGI-8 Gas Anesthesia System is intended for use with IVIS Imaging Systems to anesthetize up to 10 laboratory mice prior to and during imaging. The XGI-8 System continuously removes the waste anesthesia gas mixture from the area around the anesthetized mice to reduce, though not eliminate, user exposure to the isoflurane anesthetic agent.

MATERIALS:

• XGI-8 Table Top Gas Anesthesia System Complete with Induction Chamber
• Isoflurane, 250 ml
• f/Air activated charcoal canisters

KNOCKING DOWN ANIMALS IN PREPARATION FOR IMAGING:

Weigh the f/Air caninsters (A), record the weight and date on the side of the canisters, and replace if the weight for each filter has increased by more than 50 g from the original starting weight. If you replace a canister, RECORD THE STARTING WEIGHT!

Verify that the isoflurane vaporizer sight glass (B) is full. Fill the vaporizer if necessary; all users supply their own isoflurane. There should be no pressure in the system and the green “OXYGEN” gas flow valve (C) should be in the OFF position. You can open the valves to the induction chambers and the IVIS during this step to relieve pressure on the vaporizer.

Turn ON the evacuation “PUMP” (D) using the toggle switch on the front panel of the XGI-8 system. Confirm that the flow is greater then 9 liters per minute (LPM).

Slowly turn on the oxygen supply at the high-pressure cylinder or other supply source. Verify that the oxygen tank pressure is >250 psig. Replace if needed. Adjust the oxygen regulator to supply 55 psig.

Turn ON the “OXYGEN” gas flow valve switch using the green oxygen handle (C) located in the lower left on the front panel of the system.

Place the animals in the induction chamber. Close and lock the lid

Turn ON (flip up) the “CHAMBER” on/off toggle valve (E). This toggle controls gas flow to the Induction Chamber.

Adjust the Induction Chamber rotameter (F) to 1.5 LPM, by observing the ball and turning the valve below.

Turn on the isoflurane vaporizer flow by pushing down on the safety release (cyan arrow) and adjusting the top dial to 3% (G).

Observe the animals’ respiration. Adjust isoflurane % as needed. Animals should begin to fall asleep within 1-2 minutes. Ensure that the animals are fully asleep by gently rocking the induction chamber and seeing that there is no response.

MAINTAINING ANIMALS UNDER ANESTHESIA FOR IMAGING

Once the animals are fully induced, turn the vaporizer dial down to 1.5%

Turn ON (flip up) the “IVIS FLOW” on/off toggle valve (H). This toggle controls anesthesia gas flow to the IVIS manifold nose cones.

Adjust the IVIS Flow rotamer (I) to ensure the flow of oxygen to the IVIS. A suggested initial flow of 0.25 LPM for five adult mice may be a helpful reference for determining the appropriate flow rate for your procedure. NOTE: Oxygen is the carrier gas for isoflurane, and mice lungs do not have a high volume. There is an empty volume of tubing going from the XGI-8 to the IVIS, and it may take a few minutes to effectively purge this volume of air as Oxygen and isoflurane begin to flow to the manifold. High flow rates are unnecessary and potentially hazardous.

Turn OFF (flip down) the “CHAMBER” on/off toggle valve, stopping the flow to the induction chamber.

Release the induction chamber lid lock, and open the lid 1” to the first lock position. Allow 5 seconds for the chamber to evacuate. This will prevent operator exposure. SLOWLY open the lid, remove the animals, and transfer them to the IVIS system manifold. Close and lock the lid.

Observe the respiration of the animals with their noses in the nose cones of the IVIS manifold. Adjust isoflurane % if necessary.

If needed, another batch of animals can be induced by placing them in the induction chamber and turning ON the “CHAMBER” on/off toggle valve. The system allows for parallel operation to both the IVIS and the induction chamber.

Keep induction chamber lid shut to ensure vacuum eduction of gas from the IVIS; when the induction chamber lid is open, anesthesia gas is not being scavenged from the IVIS. As soon as models are transferred into or out of the induction chamber, close and lock the lid.

Clean the system with 70% ethanol. You may also detach the induction chambers and wash them in the sink. Alcohol based cleaners will weaken the solvent bonds of the induction chambers. NEVER, NEVER USE LPH!!! It will damage the camera.