Mon-Fri 9:00-5:00
Tissue popping out of paraffin blocks
Home » Histology FAQ  »  Embedding  »  Tissue popping out of paraffin blocks
Tissue popping out of paraffin blocks


We had a case of prostate core biopsies total 12 blocks. First 2 block cut fine and when cutter touched third block lost the core completely. The blocks were on ice face down no longer than 20 mins once faced. The other blocks looked like they were popping out and were taken for re-embedding and then sectioned.

Thoughts if this popping out could be because of

1- too much time in water?

2- processing issue?

3- condensation issue from cold plate?


What first comes in my mind is, that the tissue was a little too cold when placed into the embedding mold. That would cause an insufficient junction with the paraffin.

If there was not enough hot paraffin in the embedding mold and handling took a little bit too long, or if the tissue was rather cold and dry before putting it into the mold (cassette too long open before embedding).... something like that.

Too brittle tissue because of the processing or because it was airdried before putting it into formalin, tends to pop out of the block. But this would lead to obvious cutting problems.

Gudrun Lang

Leave a Reply