Once the end-point has been determined and decalcification is complete, the tissue must be rinsed in cool tap water to remove excess decalcification solution. Some laboratories also use lithium carbonate to neutralize the remaining acid in tissue before processing.
Rinsing tissue after decalcification is important for three reasons:
- Decalcification process is stopped so that it does not continue to impact the tissue
- Ensures that the residual acid does not contaminate reagents on the processor
- Ensures that the residual acid (specifically HCl) does not react with formalin on the processor, creating bis-chloromethyl ether