A new bone tissue process using supercritical fluid (SCF) technology has recently been described (Fages et al. 1994). Due to their unique properties of diffusivity, density and viscosity, supercritical fluids are used as selective extraction solvents. They are particularly adapted for extraction of components entrapped in a solid microporous matrix, which is the case of bone tissue. Supercritical CO 2 extraction leads to a total range in-depth delipidation of the bone porosity. Three additional steps complete the bone processing: Hydrogen peroxide is used for protein and cellular debris elimination. Sodium hydroxide for the inactivation of potentially present prions, and ethanol for final cleansing and for its well-known virucidal properties.