Summary: Rapid and accurate measures of fat and lean mass will be carried out in isoflurane-anesthetized mice, using a PixiMus dual energy X-ray absorptiometry (DEXA) device. This approach is especially attractive when it is desirable to utilize the same mice for several phenotypic measurements (e.g., when relatively few mice of a particular genotype are available), and measurements may be taken within ~5 min/mouse. Total bone mineral density (BMD, in gm/cm²) and bone mineral content (BMC, in.mg.) values are obtained automatically from the DEXA scan and will be provided to MMPC clients as part of the dataset. Regional determinations of BMD and BMC can also be provided for a nominal data processing fee by utilizing the region-of-interest (ROI) capability of the PixiMus software. When terminal studies are conducted, whole-animal DEXA data can be complemented by determinations of adiposity (catalog item D4002) by dissection and measurement of adipose depot-specific weights (summed weights of gonadal, retroperitoneal, and femoral subcutaneous fat depots divided by live weight.)