Centralized tissue culture facilities for cell culture have been in operation in our group since 1980. In this application, we are requesting continuing support for the Tissue Culture and Histomorphometry Core to provide individual investigators involved in this application with source products and services which will be needed routinely by multiple projects. Centralization of these techniques has worked will and has provided investigators with-a. Quality control of cell lines, culture techniques, and solutions required for bulk preparation of cells. b. Centralized inventory of cell lines required for these studies. c. Consistent, high quality histomorphometry. d. Experienced technicians highly skilled in these techniques. e. Optimal use of time, equipment, resources and physical facilities for these assays. A major component of our Core Laboratory is a centralized bone histology and histomorphometry facility since 1990. This has provided investigators in our group with a fast and efficient morphological analysis of the in vivo effects of a variety of agents on bone resorption, bone formation, and bone metastasis.