Presentation on theme: "Preservation of Wet Anatomical Specimens. Mr. David Cutting. Technical Officer, Museum of Human Disease, UNSW."— Presentation transcript:
Preservation of Wet Anatomical Specimens. Mr. David Cutting. Technical Officer, Museum of Human Disease, UNSW.
Old Specimens. Solution may appear discoloured/dirty. -Haemolysis (blood released from tissue). - Bile, mucous or debris in solution. -Glycerol present in solution may have aged and discoloured.
Old Specimens. What’s in the pot? Likely to be one of four solutions. Namely Proger’s, Kaiserling or Wentworth’s. There may be a mix of the three or solutions of varying grade ethanol and formalin dilutions.
Mounting Solutions. Anatomy Solution: to make 10L Sodium Acetate hydrated, 1.5g (15%) Distilled Water, 5.5L (55%) Glycerol, 3.5L (35%) *sodium dithionite may also be added at 9grm per litre of solution as a colour restorative.
Old Specimens. How can I tell what solution I’m dealing with? Smell and Viscosity. The pH is likely to have been basic (7.5) at time of potting but no accuracy after many years. Specimen records if applicable. Whatever is in it, it’s likely to be considered flammable.
Old Specimens. How do I remove the old solution? Open pot, wearing proper PPE in a fumehood or well ventilated area. Glass/Perspex? Decant solution into an appropriate container. -Sealable. Non-metallic. Suitable for corrosives.
Old Specimens. Once the solution is removed. Handle the pots very carefully as not to dislodge and damage the specimen. Rinse with water. Clean out inside with a detergent like ‘Pyroneg’ or ‘Sonidet’. Keep loose specimens in preservative.
Old Specimens. How do I dispose of the old solution? Adhere to your facility’s waste disposal guidelines. Label the waste appropriately. -Ethanol/formalin waste. Check with your OHS/Waste Management departments. Don’t pour it down the sink!
Replacing fluid. What preservative solution do I use? 1. Proger’s. 2. ‘Anatomy’ 3. Parraffin Oil. 4. Wentworth’s No.5.
‘Proger’s’ Mounting Solution. -Not suitable for fatty specimens. Will break down fat. -Many components, lengthy to make. -Most toxic solution. Pyridine/Sod. Dithionite/Formalin. + Excellent as a colour reclamation solution for old, faded specimens. + Anti-fungal qualities. + Will maintain clarity for longest.
‘ Anatomy Formula’ Mounting Solution. -Impurities in Sodium Acetate can affect refractive index and appear cloudy. -No real anti-fungal properties. -No colour restoration qualities.* + *Sod. Dithionite may be added (9grm per L) + Easy to make, few components. + Very low toxicity.
Paraffin Oil. (light grade) -Poor colour reclamation. -Cost. -Requires specimen and pot to be dry (immiscible with H20) which can damage tissue is over dried. -Not suitable for thin-walled specimens. E.g. Intestinal tract. + Will not encourage leeching of aqueous pigments from tissue. + Great clarity of solution. + Inert, non-toxic. + Does not support mould growth. + No preparation required, can be used straight from bottle.
‘Wentworth’s No.5’ Mounting Solution. -More suited to new specimens, following fixation in Wentworth’s No1. Solution. -Poor colour reclamation*. -Can tend to create a concavity in perspex pots. + Versatility. Can be used with all tissues. + Low toxicity.
Repaired Specimens. Now that your specimens are cleaned and looking refreshed... Keep them out of direct sunlight. This will bleach the tissue. If in perspex, handle carefully and do not squeeze the pot. Keep records of which solution they are kept in. Check regularly for any leaks, changes in the fluid or visible damage to the pot.
To order new pots, see or any local perspex wares manufacturer. There was a very good company in Canberra called Austral Scientific but they seem to have disappeared.http://www.plaztekscientific.com.au/ For chemicals and materials, see Feel free to me with any potential problems you may encounter. My address is in the first slide of the presentation. Good luck.