This document describes techniques for preparing and preserving pathological specimens for museum collections. It discusses receiving specimens from hospitals and laboratories, preparing them by washing in saline and fixing in formalin-based solutions, restoring color using alcohol, and long-term preservation by mounting in glycerin-based solutions. Special techniques are described for hollow organs, maceration of bone specimens, and labeling and cataloging finished museum pieces. The goal is to preserve tissue in a life-like state for teaching and research over long periods of time.

1. Dr. Anju Shrestha
PGY III, Pathology
CMCTH
MUSEUM TECHNIQUES

2. Introduction
• Pathological museums are in part historical, representing the pioneer
work of diagnosticians and therapists.
• Presents records of past states, not now encountered, or conditions of
great rarity.
• Provide the student with the basic material of his current teaching.

3. Basic museum techniques
• Reception
• Preparation
• Fixation
• Color restoration
• Preservation
• Mounting
• Special methods
• Presentation

4. Reception
• Museum specimens are collected from teaching hospitals.
• Necropsy specimens from postmortem room
• Research laboratories
Specimen should be received with full details of the patient/lesion

5. Preparation of the specimen
• One of the commonest causes of inferior specimens is contact with tap
water. The resultant haemolysis greatly reduces their value.
• Specimens should be washed only with saline, and should be kept in
saline before demonstration. Drying ruins surface appearance.
• Should not be kept in saline for more than 2 hours as autolysis sets in.

7. Fixation of the specimen
• Objective: To preserve cells and tissue constituents in as close to life
like state as possible
• Fixation stops autolysis and bacterial decomposition, and stabilizing
the cellular and tissue constituents
• Fixatives are based on formalin fixative technique.
• They are derived from Kaiserling technique and its modification.

8. • Kaiserling recommended that the initial fixation should be in neutral
formalin (KI) solution and then preserving glycerine solution (KIII)
for long term display.
• These solutions also preserve color.

9. Principle of fixation
• Specimens containing bile or stained by bile must be fixed and stored apart from
others, as they will stain them.
• Specimens undergoing fixation must not touch other specimens, or the sides of jars;
they must either lie on washed lint or be suspended by linen thread.
• Flat flaps of tissues like stomach, intestine etc. should be fixed to cork bread and left
in formalin so that they are not crumpled and irregularly fixed.
• Cystic cavities- if unopened, should be injected with fixatives. Opened ones should
be packed with cotton wool.

10. • Solid viscera should be fixed by vascular injection. For eg, brain is
fixed by injecting fixative through basilar artery.
• Lungs and limbs should be fixed by vascular injection.

11. Fixation technique
• Most widely used techniques are modification of methods described
by Kaiserling (1897).
• Originally 3 solutions were used
- First for fixing
- Second for restoring color
- Third as a mounting fluid

12. Kaiserling No. I- fixing fluid
• Formalin (40%) 400 ml.
• Pot. nitrate 30 g.
• Pot. acetate 60 g.
• Tap water 2,000 ml.
Tissue is fixed in Kaiserling No.I solution for 24 hours to few weeks
depending on the size of the specimen.

13. Kaiserling No. II solution
• The specimen is placed in 80% ethyl alcohol solution for an optimal
period for 1 hour ( upto 4 hours depending on the size of specimen), if
the specimen is discolored.
• If the specimen is left in alcohol for too long the color will fade, and
the effect is irreversible.
• This step is not required if mounting fluid used is sodium hydrogen
sulfite.

14. Color restoration
• The fixed specimen is transferred to a jar containg industrial
methylated spirit until the color is fully restored.
• The alcohol penetrates the tissue rapidly.
• Floating specimen cover with surgical gauze. The vessel should be
closed to prevent evaporation.
• Color restoration is complete in 2-8 hours, depending on the size and
character of the specimen.

15. • Restoration can be achieved by adding reducing agent- sodium
hydrogen sulfite to the mounting fluid (Pulvertaft, 1936).
• Specimen mounted show remarkably little fading even after 25 yrs.

16. Original Kaiserling No. III solution
• Glycerine 500 ml.
• Arsenious acid 1% 200 ml.
• Pot. acetate 250 g.
• Thymol 2.5 g.

17. Pulvertaft – Kaiserling mounting fluid III
• Glycerine 300 ml
• 10% sodium acetate 100 g
• 10% formalin 5 ml
• Tap water 1000 ml

18. • Camphor/ thymol- prevents the growth of moulds.
• Immediately before sealing 0.4% sodium hydrosulfite is added.
• Solution should be filtered through paper pulp under negative pressure
to remove impurities.

19. • Carbon monoxide has also been employed as a colour-retaining agent.
Schultz (1931) introduced the technique, which gives brilliant colour
contrast, but entails the risks of poisoning and explosion.
• Pure liquid paraffin can be used as final mountant after color
restoration with alcohol. It reduces discoloration of mounting fluid by
pigments in the specimen.

20. Hollow viscera
• Cut hollow viscera should be padded with cotton wool.
• Uncut viscera can be pressure inflated. Eg
- Through urethra into the bladder
- Through urethra into pelvicalyceal system
- Through trachea into the lungs
- Direct injection in case of cysts
The fixatives can be injected into such organs by Higginson syringe or
with conventional hypodermic syringe.

21. Higginson syringe

22. Preservation
• The specimen together with a duplicate label, is wrapped in gauze or
muslin and the label is attached with a piece of linen thread.
• Specimens are preserved in a rectangular earthenware tanks.
• The fluid used can be Kaiserling fixing fluid I for a period of six
months.
• After 6 months, the specimen should be treated with 80% alcohol to
restore color.

24. Mounting
• Specimens are trimmed to desired size and shape so that they fit in the
jar. All unwanted and non representative tissues are removed after
careful dissection.
• If the specimen do not remain in natural position after removal of
cotton wool packing, fill the cavities with arsenious acid- gelatin.
• Regular cuts given keeping in anatomical position.

25. • Friable specimens can be covered by thin layer of arsenious acid
gelatin.
• Bile stained specimen are soaked in solution of calcium chloride for
24 hours to avoid discoloration of mounting fluid.

26. Mounting procedure
• Museum jars and boxes
• Center plates
• Stitching specimens to center plate
• Fixing the center plate
• Filling and sealing

29. Factors affecting fixation
• Buffering
• Penetration
• Volume
• Temperature
• Concentration
• Time interval
• Position of the tissue

30. Special methods
• Maceration
- Used to demonstrate bony lesions eg; osteogenic sarcomas, osteomas and
tuberculosis.
• Calculi
- Calculi are cut in half with fine fretsaw and cut surface is polished with
sand paper.
- Dry mounting in closed jars.
• Amyloid
- Iodine technique
- Congo red technique

32. Presentation
• Museum specimen should be clearly labelled and a system of
cataloging should be employed which allows easy and rapid access.

33. Labelling
• Rectangle of Perspex sheet 1/16th of an inch in thickness which is
cemented in the center at the bottom of the outside of the box or the
bottom of the center plate.

34. References
• MUSEUM TECHNIQUES: A REVIEW BY R. J. V. PULVERTAFT From the
Westminster Hospital School of Medicine, London

35. Thank you….