Body Composition Measurement Method
The instrument determines the extent to which the protons present in lean and fat tissue perturb a magnetic field. This has been calibrated so that the output can be interpreted in terms of fat and lean masses. The technique is noninvasive, nondestructive, does not require that the animal be sedated and causes no pain or stress.
To perform these measurements the mouse is placed in a Plexiglas tube that is appropriate for its size (6 cm in diameter and restrained to a length of approximately 1-3 cm according to the size of the mouse) and is placed in the instrument's magnetic field. The measurements are controlled via a keyboard attached to the instrument computer. Readings are taken over a period of 2 to 4 minutes, after which the mouse is removed and returned to its cage.