Museum Technique
Museum specimens contain genetic information when they were collected. This archival information is very complicated to find out from samples collected recently. The museum technique can perhaps be an important method to be used for conservation genetics.
The Exhibition area of the Medical Museum is divided into various sections. The main sections are:
- History of Medicine Section
- Normal Anatomy Section
- Morbid (pathological) Anatomy Section
- Histology Section
- Haemato-pathology Section
- Radiology and Osteology Section
- Microbiology and Parasitology Section
- Interactive Corners
Purpose
The purpose of the museum technique is to collect, preserve, interpret and display specimens for scientific significance for the education of the public:
To study the original shape and colour of the specimens.
To study the history of medicine.
To demonstrate the organs in the educational sector.
Specimens may come from a few sources like hospital operation theatres, post-mortem rooms or research laboratories. It is necessary to make accurate records.
Basic steps of museum technique processing:
- Reception
- Preparation
- Fixation
- Restoration
- Preservation
- Presentation
- Mounting
Reception Of The Specimen
Any specimen received in the museum should be recorded in a reception book and given a number followed by the year (e.g 15/2022).
This number will stay with the specimen even after it is catalogued in its respective place. Written on a tie-on type label in indelible ink and is firmly attached or stitched. The reception book should contain all necessary information about the specimen (clinical, gross and microscopic findings).
Preparation Of The Specimen
An ideal specimen is received fresh in an unfixed state. However, it was obtained from the pathology laboratory after being and thus will already be formalin-fixed.
If planning to use a specimen for a museum, part of it can be kept without disturbing the museum, e.g. in a kidney, it can be bisected and one half kept aside for the museum.
Cutting Of Specimen:
- Brain knife
- Butcher’s knife
Fixation Of The Specimen
Once tissues are removed from the body, they undergo a process of self-destruction or autolysis, which is initiated soon after cell death by the action of intracellular enzymes causing the breakdown of protein and eventual liquefaction of the cell. The objective of fixation is to preserve cells and tissue constituents in as close to a life-like state as possible and to allow them to undergo further preparative procedures without change. Fixation arrests autolysis and bacterial decomposition and stabilizes the cellular and tissue constituents.
Before mounting, specimens should be trimmed according to specifications and fixed in fixatives to avoid decomposition or distortion. The volume of the fixative should be ten times the volume of the specimen.
An insufficient amount of fixative used results in the cloudiness of the solution. The colour of the specimens would not be the same and varies from their natural colour.
Specimens should be suspended in the fixative and avoid contact with the Perspex container. Ensure the condition of fixation.
The penetration rate of the fixative into some organs such as the liver, kidney and spleen is slow. It is done by direct injection of fixative.
10% formalin was used. However, the modified solution contains some additives to improve the specimens displayed. Examples of some of the methods are Romhanyi’s Method, Wenthworth’s Method and Kaiserling’s Method.
Most fixatives used today in museums are based on a formalin fixation technique derived by Kaiserling.
Restoration Of The Specimen
It is required to restore the specimens, as they lose their natural colour on fixation.
The recommended method is the Kaiserling II method. After this step, the specimen is ready for preservation.
Preservation Of The Specimen
The final solution in which the specimen will remain for display.
Presentation Of The Specimen
Initially, all museum specimens were mounted in cylindrical jars and sealed with sheep bladder walls. Later they were replaced by rectangular glass jars.
Museum Techniques were better than cylindrical ones as the flat surfaces afforded a clear view of specimens without distortion. It is covered by rectangular glass plates. These jars can be purchased readymade or assembled by the museum, as per need. Nowadays, Perspex jars are also available, Which are lighter than glass jars. However, they cannot be used to store specimens fixed in alcohol or methyl salicylate as they react with plastics.
Mounting Of The Specimen
To supports the specimen within its jar, it is attached to the specimen plate or rectangular bent glass rods. It is done by tying with nylon threads. The double knots should be on the specimen surface.
