Kathryn Heivilin, CPIA, RBP
Senior IACUC Manager
UM Biosafety Officer
Open-Drop Isoflurane Anesthesia for Field Studies
Last Date Reviewed: November 29, 2017
2. Cotton gauze pad
3. Tea strainer or conical tube with pre-drilled holes
4. Bell jar or wide-mouth glass container (with known volume). Any type of
container with a secure lid may be used, provided it is constructed of
B. Mice will remain deeply anesthetized for approximately 30 seconds following
exposure in the induction chamber. This method can be used for
blood sampling, tail
C. Close constant monitoring of animals is essential during induction and anesthesia
temporary field station – open two sides of the wall tent for air circulation.
cc volume of the anesthesia jar.
1. Place the cotton pad inside a small container (metal tea strainer). The use of
the tea strainer ensures that the animal does not contact the isoflurane-soaked
pad, which can cause skin irritation and potential overdosing since isoflurane
2. Transfer animal to anesthesia jar and close lid tightly. Monitor animal closely.
Within approximately one minute the animal will become anesthetized. Initially,
respiratory rate will increase and then decrease. Clinical indications of a
anesthesia levels (i.e., to ~80- 100 breaths per minute).
3. Allow the animal to remain at a deep anesthetic plane for ~10 seconds
before proceeding. Quickly, yet carefully, remove the animal from the jar
4. Apply a noxious stimulus (i.e., toe pinch) to ensure adequate plane of
anesthesia. If no response is noted, the procedure can be initiated. If
5. The animal will remain deeply anesthetized for approximately 30 seconds
following exposure to the isoflurane in the induction chamber.
6. If the animal reaches a lighter plane of anesthesia during the procedure,
evidenced by increased respiratory rate, whisker twitch, or
until the animal again reaches a deep plane of anesthesia.
7. If anesthetizing multiple animals, proceed as described above but if the
subsequent animal does not reach a surgical depth of anesthesia,
8. Allow the animal to recover on a piece of clean paper towel in a bedding-free
cage. Monitor the animal closely until it is fully recovered.