Specialized tools are necessary to evaluate skeletal phenotypes of transgenic and knockout mouse models.[unreadable] The Skeletal Phenotyping Core, under the direction of Dr. Quarles, has developed the necessary procedures[unreadable] and services to perform in vitro and in vivo analysis of mouse models. The major functions of the Core are[unreadable] to provide: 1) skeletal imaging using X-ray, DEXA and microQCT; and 2) bone tissue processing for[unreadable] quantitative histology, immunohistochemistry, and in situ hybridization. In addition, the Core provides[unreadable] additional services as needed, including assessment of biomarkers in serum; real-time PCR for differential[unreadable] gene expression profiling of bone; cell culture models for assessing osteoblastic function ex vivo; and a[unreadable] mouse clinical research unit for physiological, pharmacological, genetic and surgical interventions. Finally,[unreadable] the Core will serve as a resource for consultation and training of Center investigators in the principles,[unreadable] methods and analyses of bone tissue histology.