Abstract: A process and apparatus are disclosed for the demineralization of ground bone particles or pieces of cancellous or cortical bone. The apparatus includes multiple solution reservoirs which supply solutions to be pumped into one or more columns filled with bone samples to be demineralized. Solvent outflowing from the column(s) can be monitored for pH, calcium ion concentration or conductivity as a basis for determining when demineralization is complete. During the delipidization phase of processing, lipid solute can be monitored by photometry, or a small assay of the eluent can be dropped into deionized water to see whether a precipitate develops. Flow through the apparatus, including the types and amounts of solutions to be flowed through the apparatus, can be manually or computer controlled.