McMullan1 project protocol

Body composition and forced endurance in aging females of 50 Collaborative Cross strains of mice   (2017)

McMullan RC, Pomp D, Pardo-Manuel de Villena F

Project protocol - Contents

Workflow and sampling

Data collected
Weigh mice Scales
Body weight
2 Assess body composition
MRI Lean mass and fat mass
3 Measure forced endurance Treadmill Endurance (distance traveled)

Equipment and supplies

  • Scales
  • Whole body MRI (EchoMRI 3-in-1 Body Composition Analyzer, EchoMRI, Houston TX)
  • Treadmill (Exer-3/6 Treadmill, Columbus Instruments, Columbus OH)

Reagents and solutions

  • Disinfectant

Procedure: Body weight and body composition

  1. Mice are weighed prior to MRI.
  2. Body composition is assessed using whole body MRI between 0700 and 1200h.
  3. Fat mass and lean mass percentages are calculated relative to body weight.

Procedure: Forced endurance

  1. Forced endurance is measured on a treadmill, starting one day after body composition is assessed.
  2. There are three adaptation days followed by one maximal performance day. See detailed treadmill protocol here.
  3. Maximal forced endurance (distance traveled) is recorded when a mouse fails to run (either from the inability to continue treadmill running or the refusal to continue running despite extra stimulus from the shock grid or prodding).

Data collected by investigator

  • Body weight
  • Body composition
    • Fat weight
    • Fat percentage
    • Lean weight
    • Lean percentage
  • Forced endurance (distance traveled)