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1. The specimen is allowed sufficient time for it to be fully fixed with 10% formol calcium (at least 24 hours after removal from the body) before processing is commenced.

2. If the specimen is too large, it should be trimmed so that adequate size block(s) are taken from the part(s) required for examination. Should trimming be necessary, then advice must be sought from an experienced MLSO.


1. 70% alcohol 1 hour

2. 90% alcohol 1 hour

3. 100% ethanol x 2 1 1/2 hours

4. Infiltrating solution (i) 1 hour

5. Infiltrating solution (ii) overnight

6. Embedding solution


1. Specimens must only be processed under an operational fume hood.

2. Specimens are agitated continuously on a roller mixer for steps 1-4.

3. Waste solutions containing alcohol may be discarded down the sink.

4. Any waste solution containing resin monomer(s) must be discarded in a plastic beaker under a fume hood and polymerised before disposal.


--JB-4 resin component A 9g

--Methyl methacrylate monomer 1g

--Dried benzoyl peroxide 45mg

Make up solution under a fume hood in a large glass vial. Benzoyl peroxide must be dissolved before use by agitating on a roller mixer.


--Infiltrating solution (pre-chilled) 10g

--JB-4 resin component B 250µ

Mix components on a roller mixer before use.


1. Use an open moulding plastic tray partially immersed in water inside a dessicator.

2. Fill each mould using a Pasteur pipette with embedding solution to just above the level of the well.

3. Orientate the label using a pair of forceps so that it is parallel to the well with the number faced down.

4. Orientate the specimen in the well so that the surface to be cut is faced down.

5. Place a plastic stub which has a central hole punctured in it over the well.

6. If necessary top up gently with more embedding solution.

7. Replace the lid on the dessicator and fill the chamber with oxygen-free nitrogen.

8. Seal the chamber and allow 2 hours for the resin to polymerise.

NOTE: No responsibility is assumed by The University of Nottingham or the Queens Medical Centre NHS Trust for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. It is the users responsibilty to ensure that all procedures are carried out according to appropriate Health and Safety requirements.

© Copyright 1997 University of Nottingham Medical School Division of Histopathology. This page was last built on Mon, May 5, 1997 with Frontier. Thanks for looking in. Comments to James.Lowe@nottingham.ac.uk