5. Basic museum techniques
Any specimens for museum are handled by ;
Reception
Preparation
Fixation
Colour Restoration
Preservation
Mounting
Special methods
Presentation
6. Reception of the specimen
Any specimen received in the museum should be
recorded in a reception book and given a number
followed by year.(eg.17/2018)
This number will stay with the specimen even after
it is catologued. written and tied firmly or stitched
to the specimen
The reception book should contain all necessary
information about the specimen (clinical, gross and
microscopic findings).
7. Preparation of the specimen
An ideal specimen is received fresh in unfixed
state.
However, it is mostly obtained from the pathology
lab after being examined ,thus already be formalin
fixed.
If planning to use for museum , a part of it can be
kept without disturbing for museum.
10. Fixation of specimen
The objective of fixation is to preserve cells and
tissue constituents in a close life-like state as
possible and to allow them to undergo further
preparative procedure without change.
Fixation arrests autolysis and bacterial
decomposition and stabilizes the cellular and tissue
constituents.
11. Cont…….
Prior to mounting, specimen should be trimmed
accordingly and fixed in a fixative.
The volume of fixation should be 10 times the
volume of the specimen.
Insufficient amount of fixation used will result in
cloudiness of the solution.
Specimen should be suspended in the fixative and
avoid contacting with the Perspex container.
12. Penetration of fixative to some organs are very slow,
this can be overcome by direct injection of fixative.
Basically, 10%formalin is used.
modified solutions containing addictives to improve
specimen display
Eg.) Romhanyi’s method
Wenthworth’s method
Kaiserling’s method
Most of the fixative used today are based on a
formalin fixative technique derived by
kaiserling(1897)…
13. Kaiserling fixation
Kaiserling recommended that ;
the initial fixation be a neutral formalin(K1)
then transfer into the final preserving glycerin
solution (K III) for long term display.
-colour preservation is also maintained with these
solutions.
K 1 K III
14. Fixation technique
The technique most widely used is modification of
method described by kaiserling -1897.
original technique
fixing
restoring colour
mounting fluid
15. Fixation of specimen
The specimen needs to be kept in a large enough
container which can accommodate specimen along
with 3-4 times volume of fixative.
Specimen is stored in K-1 solution for 1 month
(depending on the size of the specimen)
The specimen should not rest on the bottom of the
jar artificial flat surface will be produced on
hardening.
16. Fixation keiserlings I solution
Formalin(40%) 400 mL
Potassium
acetate
60 gm
Potassium nitrate 30 gm
Distilled water 2000 ml
17. Colour Restoration of specimen
It is required to restore the specimen, as they lose
their natural colour on fixation.
Method kaiserling II method
specimen washing in running water
transfer to 95% alcohol for 10 mints -1hr
(depending on the size of specimen)
the specimen is then kept and observed
for colour change 1-1.5 hrs.
18. Kaiserling II solution
Alcohol (ethyl) 95%
Store specimen in this solution for 10mints to 1 hr
depending on size of specimen.
Rejuvenator solution
Pyridine 100ml
Sodium hydrosulphite 100gm
Distilled water 4 litres
Formalin decreases the natural colour of the specimen.
Rejuvenator solution restores the colour
Pulvertaft (1936)method of restoring the colour by adding reducing
agent to mounting fluid
19. Schultz -1931
Carbon monoxide has also been employed as colour
retaining agent.
This technique gives brilliant colour contrast, but has
a risk of poisoning and explosion and also colours
are unrealistic.
20. Preservation of specimen-
mounting
The recommended solution is kaiserling III .
This is the final solution in which the specimen will
remain for display. It is based on glycerine solution.
Kaiserling III solution:
Potassium acetate 250 gm
Arsenious acid 1% 200ml
Glycerine 500ml
Distilled water 1000 ml
Thymol crystals 2.5 gm
Leave solution to stand for 2-3 days before using to ensure proper
mixing of chemicals
Add 1% pyridine as stabilizer. This solution acts as a permanent fixative
21. Pulvertaft-kaiserling mounting
fluid III
Glycerine 300 ml
Sodium acetate 10% (PH 8) 100 g
10% formalin 5 ml
Tap water 1000ml
Israel and young (1978) pure liquid paraffin as the final mountant
after colour restoration with alcohol
23. Preservation
The specimen together with a duplicate label, is
wrapped in gauze or muslin and a label attached
with a piece of linen thread.
Specimens are preserved in a large rectangular
earthenware tank
Fluid used kaiserling fixing fluid I 6 months.
24. Mounting
Specimens are trimmed to desired size and shape
that fits into the jar
In cotton wool packed specimens cavities should
be filled with arsenious acid gelatine.
Specimens which are friable may be covered with
a thin layer of arsenious acid-gelatine (wentworth
1947) also used locally to hold fragments such as
blood clots in position.
26. Maceration
It is used to demonstrate bony lesions such as
osteogenic sarcomas , osteomas and tuberculosis.
This method helps in preservation of even the finest
bony spicules.
trim off the excess soft tissues
boil in tap water / very dilute (N/100)sodium
hydroxide
A gross method for hard compact bone is;
autoclaving in N/10 sodium hydroxide for 5 mints
27. Degreasing and bleaching
after removal of soft tissue by any above method
bone is immersed in chloroform for 3-4 hrs
remove fat
specimens are dried in a incubator
bleached in Hydrogen peroxide
28. Mounting
Macerated bones are mounted dry.
Mounted on a central plate or on Perspex box
The specimens fixed with nylon wire
29. Calculi
Calculi are cut in half with a fine fretsaw , and cut
surface polished with sand paper.
Dry mounting:
cut surface of calculi shows laminations which
can be dry mounted in closed jars so that remains
dust free.
Gelatin mounting:
which can be kept under formalin
30. Cont……..
Marks are made on perspex sheet around
positioned stones and holes drilled .
So that the stone fits into the gap , which is placed
in position using perspex cement.
Then the perspex sheet is mounted in a glass jar
and the lid is sealed.
31. cont,……..
Alternative method is to make depressions in
thermocol slab , of the size of the calculi.
So that the cut surface and external surface of
calculi is stuck on it with glue.
Once dry, the thermocol sheet is placed in a clean
glass jar and sealed.
32. Transparent specimens
It is used in the preparation of transparent
specimens are dependent on the replacement of
the tissue fluids by fluids of higher refractive index.
Dawson’s technique Spalteholz technique
33. Amyloid
Iodine technique
slice of formol fixed tissue
place in Lugol’s iodine+1%sulphuric acid mixture.
leave for 1-2 hrs
wash in running tap water
mount in liquid paraffin
34. Congo red technique
fix in K 1
specimen are immersed in 1% congo red 1 hr
transfer to saturated solution of lithium carbonate
2 mints
differentiated in 80% alcohol
normal arteries and veins tend to retain
the colour
specimens are mounted in K III.
35. Haemosiderin
fix in K 1
Stain with solution of equal parts of 10% HCL and
5% aqu.potassium ferrocyanide
Wash in running water for 12 hrs
Freshly prepared specimens are mounted in 5%
formol saline prevents colour diffusion
36. Presentation of specimen
Specimens should be clearly labelled and a system
of cataloguing should be employed which allow
easy and rapid access.
37. Drawbacks of the routine
formalin fixed techniques
Irritating odour
Bleached colourless parts
Do not give naturalistic idea
Difficulty in maintaining the sections
The architecture, dimension, branching patterns
are almost impossible to imagine In the dissection.
38.
39. Plastination
“ a technique of preparation of dry,
coloured, non-toxic, durable,
odourless, natural looking
specimens”
40. History
Developed by Dr.Gunther Von Hagens in
Heidelberg, Germany in 1978.
Water and lipid in biological tissues are replaced by
curable polymers (silicon,epoxy,polyester)
41. Cont……..
Silicone:
it is used for whole specimens and thick body
and organs slices to obtain the natural look.
Epoxy:
this resins are used for thin, transparent body
and organ slices.
Polyesters-copolymer:
it is exclusively used for brain slices to gain an
excellent distinction of gray and white matter.
43. Fixation:
conventional fixation method
Dehydration :
by acetone
intermediary solvent during impregnation
Forced impregnation :
it is the central step in plastination
vacuum forces the acetone out and the polymer
into the specimen.
Hardening (curing):
specimen is hardened by exposing it to the
gaseous hardener (silicone), or by UVA-light and
heat (polyester, epoxy)
44.
45. Methods of Plastination
The silicon S-10 standard procedure
(for opaque and flexible specimens)
The COR-TECH room temp.procedure
The Epoxy E 12 Procedure
(thin,transparent and firm body/organ slices)
The polyester P35/P40 procedure
(semitransparent and firm brain slices )
47. Materials used
Jars for storage and processing
Acetone
Silicone rubber
Resin, catalyst, accelerator
Colour paints
Dissection instruments
Syringes , needles.
48. Whole organ Plastination
Helps in better understanding of total structures
and relationships.
Method:
wash the specimen in tap water
immersion in preservative
Time required for complete fixation is 2-3 days.
95% alcohol 280 ml
Formalin 1320 ml
Glycerin 80 ml
Phenol 120 ml
Distilled water 800 ml
49. Procedure
wash formalin in running tap water
transfer the specimen to acetone jar
transfer to a jar of resin -1 to 2 weeks
immerse the specimen in the mixture of resin
general purpose resin
catalyst (5%)
accelerator (0.1%)
after few hrs specimen becomes non-sticky
specimen is mounted and properly oriented
50.
51. Sheet Plastination
Useful method for the preparation of thin
transparent or thick opaque body sections
The whole body may be cut into slices and stored
dry.
The inner relationships are best appreciable.
52. Sheet Plastination-Method
Deep freeze -24hrs ,thin sections are made at 1cm
Section are casted in the form of sheet
The 2 glass sheets of 4mm are separated by a rubber
tubing of 6-8mm diameter clips, hold the glass
sheets together and make a leak proof chamber.
The processed sections are immersed in the chamber
(resin + catalyst + accelerator)
After 24hrs clips are removed and glass sheets are
separated from the resin.
Sheet edges are trimmed, polished and labelled.
53. Luminal cast Plastination
“useful to study the dimensions and architecture of
different cavities of organs and to study the tubular
structures (arteries, veins, etc…)
Principle:
filling up the lumen with material and dissolving the
surrounding tissue .
Used for;
bony labyrinth
lungs
vascular pattern of
kidney, liver ,lungs etc…
54. Luminal cast-method
Clean the lumen under tap water
Keep the specimen in KOH solution for 1-2 hrs
Again clean the specimen under running tap water
and dry
Filling the lumen by a mixture containing resin,
catalyst and hardener
After 1 day cast is obtained by removing the
surrounding tissue.
55. Why Plastination is preferable
and better museum
techniques??
Provides very unique specimen at a very low cost
equivalent to the international quality.
Has simple protocol
Best suited for;
teaching purpose
designing newer surgical procedure
practice skills
research purposes.
56. Advantages
Specimens are dry and easy to handle, store,
transport and long lasting
There will be no formalin fume irritation on the dry
specimen
57. Disadvantage
Costly procedure
Time consuming
Required skilled technical support to carry out the
procedure and in handling the equipment
Chemicals used such as acetone are highly
inflammable
58. Taxidermy
Taxidermy is the preserving of an animal's body via
stuffing or mounting for the purpose of display or
study.
The word taxidermy is derived from the Greek
words "taxis" and "derma". Taxis means "to move",
and "derma" means "skin“.
Inferior quality of specimen is contact with water –hemolysis washed only with saline but not more than 2 hrs
This step is not needed when using sodium hydrogen sulphite mounting fliud / colour rest complet in 2-8 hrs
Sodium hypo sulphite fading is less and for 25 yrs
Thymol to prevent mold
Hydrosulphite should be 0.4 % not exceed 0.4 if colour restoration must be rapid 0.6% must be added but this should be avoided coz white preceptation may form /sodium acetate impuritysol is not crystal clear filter by paper pulp under –ve pressure /young method reduces the discolouration of munting fluid by specimens pigments
Dpx-1.518-1.521 20o c
6 month after 80% alcohol is used to restore the colour
Except specimen with hemochromatosis coz with in 3 months colour diffuses and become milky white
Water and lipid in biological tissues are replaced by curable polymers (silicon,epoxy,polyester)