Results are presented which document the feasibility and utility of human trabecular bone explants for in vitro bone research. This approach is advantageous because it allows bone cells to maintain their natural orientation on the endosteal surface, and keeps surrounding marrow intact--thus retaining the immediate local microenvironment. In addition, bone cells are not exposed to transient, but sometimes harsh, isolation procedures. Data are presented which show greater initial bone cell numbers from younger donors and the change in these numbers over culture periods up to 21 days. A technique is presented which achieves single and double tetracycline label incorporation into the mineralizing front of bone explants in vitro using a pulse-chase methodology.