GMC18 project protocol
Bone mineral density, body composition, and X-ray analysis of 8 inbred founder strains of the Collaborative Cross (2020)
German Mouse Clinic and Department of Infection Genetics, HZI
With: Hrabě de Angelis M, Fuchs H, Gailus-Durner V, Mayer-Kuckuk P, Hans W, Lengger C, Kollmus H, Schughart K
See also: GMC18 animal documentation
German Mouse Clinic: Phenotyping Pipeline
Dual Energy X-Ray Absorptiometry (DXA) and X-Ray: 17-18 wks of age
||Body weight and length
||Dual-energy X-ray Absorptiometry (DXA)
||Body composition and bone mineral density
- Balance: Ohaus (AV213C)
- DXA analyzer: Norland Stratec (pDEXA Sabre)
- X-Ray machine: Faxitron (MX20-DC-12 X-Ray scanner)
- Software: iX-Pect (for Faxitron)
- Cleaning solution
Procedure: Dual Energy X-Ray Absorptiometry (DXA) and X-Ray
- Mice are anesthetized with ketamine-xylazine (i.p.) and monitored until they become unconscious.
- Mice are weighed and the length of the mouse is measured with a disinfected ruler (measure length starting from the nose at 0 cm to the beginning of the tail (accuracy within 0.1 cm)).
- The mouse is placed in the DXA analyzer (calibrated daily using phantoms from the manufacturer) and a snout scan is performed.
- The area of interest is optimized and a measure-scan performed (exposure dose is 300 µSv).
- Regions of interest are defined for data analysis (whole body excluding the head).
- The mouse may go directly to the X-Ray machine (below). If not, the mouse is removed (once the image has been captured) and is placed on a heated mat (37°C) in a clean cage and monitored closely until consciousness is regained.
- Raw data are transformed by accompanying software into bone and non-bone components, and fat and lean mass are determined.
- An anesthetized (ketamine-xylazine) mouse is mounted onto an X-Ray permeable plate; the tail is curved along the left side of the body (used to enable identification of the X-Ray as dorsal or ventral).
- The plate is inserted into the X-Ray machine.
- The machine is set to a voltage of 25 kV with an integration time of 40 ms.
- An image is taken using the iX-Pect software.
- The mouse is removed and placed on a heated mat (37°C), in a clean cage and monitored closely until consciousness is fully gained.
- Body length
- Total tissue mass
- Fat tissue mass
- Lean tissue mass
- Bone mineral density
- Bone area
- Bone mass
- X-Ray *
- Number of lumbar vertebrae
* Many other X-Ray parameters are available in the Supplemental data file (see GMC18 Downloads)