Calcified tissue is a universal concern among histotechnologists. Not calcium-free tissue is challenging to work with and yields poor diagnostic results. Decalcification refers to the process by which calcium salts are removed from a tissue sample. Most human tissue grossed for diagnostic pathology must be decalcified before it is processed for paraffin embedding and microtomy. Calcifications and the calcium found in bone must be removed for paraffin sectioning to be possible. Demonstrating bone and its components are more complex than other tissue types. Bone sections and nodular calcifications can pop out of paraffin blocks during microtomy and will damage blades/ knives if they are not decalcified. Even the most minute calcifications can render paraffin sections useless and unreadable.
When creating a decalcification protocol, it is important to consider the following:
- Type of tissue that is being decalcified
- The degree of calcification
- The extent of pathologic review, which could include specialized studies
- Subsequent staining procedures
A good decalcifying agent should:
- Take the least amount of time to remove calcium
- Cause little or no damage to cells, with the least disruption to tissue morphology
- Not alter staining
This course simplifies the decalcification process and provides valuable techniques to work with calcified tissue successfully.
