Museum techniques

museum in pathology

1. MUSEUM IN PATHOLOGY

2. ●Pathological museums are in part historical,
representing the pioneer work of diagnosticians
and therapists.
●Presents records of the past states, now
infrequently encountered.
●Provide the students with basic material of their
current teaching

3. ●BASIC MUSEUM TECHNIQUES
–Reception
–Preparation
–Fixation
–Color restoration
–Preservation
–Mounting
–Special methods
–presentation

4. ●RECEPTION
–Source: specimen are mostly collected from
●Teaching hospitals – surgically resected specimen from
operation theatres.
●Necropsy specimen from postmortem room
●Research laboratories
–Specimen should be received with full details of the
patient and the lesion.

5. ●PREPARATION OF THE SPECIMEN
–Contact of the specimen with tap water –
commonest cause of inferior quality of specimen.
Resultant hemolysis greatly reduces the value of
preservation.
–Should be washed in saline and kept in saline
before demonstration. Drying ruins surface
appearance.
–Should not be kept in saline for more than 2 hrs 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 used are based on formalin fixative
technique.
–They are derived from Kaiserling technique and its
modification.

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

9. ●Principle of fixation
–Specimen containing bile or stained by bile must be
fixed and stored apart from other specimen.
–Specimen undergoing fixation must not touch other
specimen or the sides of the jar; they must either lie
on washed lint or should be suspended by lenin
thread.
–Flat flaps of tissues like stomach, intestine etc. should
be fixed to cork board 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
method described by Kaiserling (1897)
–Originally 3 solutions were used
●First for fixing
●Second for restoring color
●Third as a mounting fluid.

12. Keiserling no I – fixing fluid
●Formalin 40% - 400 ml
●Potassium nitrate – 30 g
●Potassium acetate – 60 g
●Water up to 2000 ml
–Tissue is fixed in Kaiserling No. I solution for 24 hrs
to few weeks depending on the size of the
specimen.

13. Keiserling no. II solution
–The specimen is placed in 80% ethyl alcohol
solution for an optimal period for 1 hour ( up to 4 hrs
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 UDED IS SODIUM HYDROGEN SULFITE

14. ●COLOR RESTORATION
–The fixed specimen is transferred to a jar containing
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 hrs,
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
–Glycerin 500 ml
–Arsenious acid 1% in 200 ml
–Potassium 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
●Camphor/ thymol – prevents the growth of moulds.
●Immediately before sealing 0.4% sod. Hydrosulfite is added.
●Solution should be filtered through paper pulp under
negative pressure to remove impurities.

18. ●Carbon monoxide has also been employed as
color -retaining agent. It gives brilliant contrast
color. Risks – poisoning, explosion. The colors
are unrealistic.
●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

19. ●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. ●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 mths, the specimen should be treated with
80% alcohol to restore color.

23. ●MOUNTING
–Specimen 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.

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

25. ●Mounting procedure
–Museum jars and boxes
–Center plates
–Stitching specimens to center plate
–Fixing the center plate
–Filling and sealing

27. ●Factors affecting fixation
–Buffering
–Penetration
–Volume
–Temperature
–Concentration
–Time interval
–Position of the tissue

28. SPECIAL METHODS
–Maceration
●Used to demonstrate bony lesions eg. osteogenic sarcomas, osteomas
and tuberculosis
●Enables the preservation of even finest bony spicules .
–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

29. PRESENTATION
–Museum specimen should be clearly labeled and a
system of cataloging should be employed which
allows easy and rapid access.

30. LABELING
–Rectangle of perspex sheet 1/16 th 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.

31. THANK YOU