The Scientific Core has three major components: 1) Cell cultures, 2) Animals and 3) Microscopy. The Core will assist each of the projects by providing reagents and support services. These include characterized cells, breeding, genotyping, and phenotyping of mouse models, microscopy, in situ immunofluorescence imaging and histology. Scientific and technical support includes: 1. Routine isolation and maintenance of primary fetal rat calvarial-derived osteoblasts, marrow cells and calvarial osteoblasts from transgenic/knock-in mice as needed. 2. Maintenance of various osseous and non-osseous cell lines and cell lines with transgenes. Preparation and sterility testing of cell culture media, screeening of serum lots and enzyme reagents to ensure uniformity of cultures. 3. Monitoring growth and differentiation properties of cell lines for phenotype stability. 4. Preparation of adenovirus stocks of Runx2 proteins. 5. Maintenance of Runx2 knock-in/mutant mouse colonies as required for all three projects. This includes breeding, tagging, and identifying positive and negative mice by Southern blot or PCR analysis. 6. Routine preparation of embryos or tissues for phenotype characterization, which may include either whole embryo (3-Gal staining, frozen, plastic or paraffin embedding, sectioning and staining, and jnCT analyses. 7. Preparation of total cellular RNA and nuclear matrix proteins from tissues and cell lines. 8. Characterization and quality control of all antibodies used for in situ immunofluorescence. 9. Maintenance of all microscopes and software applications. 10. Data management of quantitative procedures to characterize distribution of wild type and mutant Runx2 transcription factors and their co-regulatory proteins.