Decalcification and End-Point Determination

The page below is a sample from the LabCE course Tissue Decalcification for Paraffin Processing. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

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Decalcification and End-Point Determination

The most important aspect of the decalcification process is determining when enough calcium has leached out of the specimen to be suitable for processing. Failure to completely decalcify tissue results in poor microtomy, as well as excess basophilic staining with H&E. Failure to stop the decalcification process in time results in loss of basophilia and increase in eosin staining, with a lack of nuclear staining. Compare the two images of decalcified bone tissue for staining differences.
Methods employed to determine the end-point of decalcification:
  • Mechanical or physical methods
  • Chemical methods
  • Radiography or x-ray methods
  • Weight change