Step Procedure performed Equipment Data collected 1 Mice implanted with subcutaneous microchips for identification microchip applicator - 2 Mice monitored once daily for health and longevity microchip reader lifespan 3 Old moribund mice sacrificed, other causes of morbidity considered for early termination microchip reader lifespan
- Microchip identification system (Locus Technology, Inc., Manchester, MD, USA)
- Caps, face masks, disposable gowns, shoe covers, and gloves
a. To determine the time and type of death, mice are inspected at least once daily.
b. A mush of ground pellets and water is placed on the cage bottom for older mice too weak to obtain food.
c. Moribund mice are sacrificed if severely ill and judged they would not survive another 48 h.
d. A mouse is considered severely moribund if it exhibits more than one of the following six clinical signs: inability to eat or drink; abnormally low body temperature; severe lethargy (reluctance to move when gently prodded with forceps); severe balance or gait disturbance; rapid weight loss for a week or more; an ulcerated or bleeding tumor.
e. The age at which a moribund mouse is sacrificed is taken as the best available estimate of its natural lifespan.
f. Mice dying abnormally, such as those experiencing severe bites, are censored.
g. Mice are considered to have severe bites if their wounds cover over 20% of the skin or are bleeding or infected and do not significantly improve after a week of antibiotics.
Data collected by investigator