Decalcification of Bone Tissue

Abstract

Bone is among the hardest, most dense tissue encountered at the bench by histotechnologists. In order to achieve acceptable 3–6-μm sections of bone, the technologist surrounds and infiltrates the material with a media of relatively similar density to form a more homogenous construct. For studies involoving mineralization, the technologist may choose one of several polymer resins, which produce a block close to the hardness of the bone itself. For studies of intracellular detail in which extremely thin sections of marrow are preferred, the technologist may choose a “softer” polymer that can readily produce sections of bone marrow at 1.5–2 μm. Frozen sections of some samples can also be achieved using very cold temperatures and harder tungsten carbide blades. These are usually specialized procedures, which are not available to most histopathology laboratories. Because paraffin processing of tissue is the most widely used methodology in histologic slide preparation, procedures have been developed to allow specimens to conform to this routine histologic preparation. In order to accomplish this, bone specimens must be made compatible with the embedding media and sectioning apparatus associated with this process. Because the paraffin used in this process is significantly softer than most bone, the bone sample must be treated to take on this softer characteristic in order to be sectioned. This treatment known as decalcification.