Preservation of Wet Anatomical Specimens.

Mr. David Cutting.Technical Officer, Museum of Human Disease,

UNSW.

davecutting@unsw.edu.au

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.

Proger’s Solution:

to make 11L (10,990mL)

Sodium Dithionite (Sodium Hydrosulphite), 90g (0.81%)

Di Sodium Hydrogen Orthophosphate, 125g (1.13%)

Potassium Di Hydrogen Orthophosphate, 10g (0.09%)

Formalin 37-40%, 450mL (4.0%)

Pyridine, 90mL (0.81%)

Distilled Water, 6.2L (56.4%)

Glycerol, 4L (36.3%)

Mounting Solutions.

Wentworth’s No.5 Solution:

Per 9L (9057mL)

Sodium Acetate hydrated, 300g (3.31%)

Tri Sodium Orthophosphate, 7.5g (0.08%)

Formalin 37-40%, 150mL (1.65%)

Distilled Water, 7.5L (82.8%)

Glycerol, 1.5L (16.5%)

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 http://www.plaztekscientific.com.au/ or any local perspex wares manufacturer. There was a very good company in Canberra called Austral Scientific but they seem to have disappeared.

• For chemicals and materials, seehttp://www.livingstone.com.au/http://www.vitalmed.com.au/http://ajaxfinechem.com/http://www.sigmaaldrich.com/australia.html

• Feel free to email me with any potential problems you may encounter. My address is in the first slide of the presentation. Good luck.