[Histonet] RE: Histonet Digest, Vol 96, Issue 24 reprocessing Other methods

Steve McClain SteveM <@t> mcclainlab.com
Thu Nov 17 05:23:59 CST 2011

Not appropriate for your current mamafufu, 
But here are two 're-processing' methods used in our lab for small fixed tissues.

Method 1 where the tissue was bit too large for a short processing cycle and the center of the block is sub-optimally infiltrated or soft and needs more paraffin time.
Cutting can be improved by melting the block in a tissue mold, then change the paraffin and allow to sit for 30-60 minutes and re-embed in new paraffin.

Method 2 Cleaning cycle method
where small FIXED tissues were processed on too short a cycle, e.g., 4 mm punch biopsy on a 1 hour process (instead of a 4 -6 hour process) 
we have used this method for taking paraffin blocks back to alcohol.
Melt blocks in correctly-sized molds in embedding center.
Re-wrap tissues (carefully) and place back into cassettes and verify each lid is closed.
Place in VIP-type processor with an automated cleaning cycle.
Replace the purges with clean reagents.
Run the cleaning cycle through the purge xylene-alcohol on the tissue processor, when completed- do not run through the water purge. 
Re-process (correctly) beginning in 95% alcohol.

Steve A. McClain, MD
631 361 4000

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