|Year : 2016 | Volume
| Issue : 3 | Page : 131-133
Wax embedding technique of mounting anatomy museum specimens
Sushant Swaroop Das, Kahkashan Jeelani, Neelam Vasudeva
Department of Anatomy, Maulana Azad Medical College, New Delhi, India
|Date of Web Publication||7-Oct-2016|
Dr. Sushant Swaroop Das
Department of Anatomy, Maulana Azad Medical College, New Delhi - 110 002
Source of Support: None, Conflict of Interest: None
Introduction: Anatomy museum specimens are used as a visual undergraduate teaching aid, which are gradually replacing cadaveric teaching as nowadays human cadavers are becoming difficult to obtain. Materials and Methods: Paraffin wax was used for mounting anatomical specimens to replace age-old methods of using plaster of Paris and glass sheets. Results and Conclusion: Wax mounting of specimens resulted in better understanding of anatomical details and relations of structures. This technique is easy to use, inexpensive, and reproducible.
Keywords: Mounting, museum specimens, paraffin wax, teaching aid
|How to cite this article:|
Das SS, Jeelani K, Vasudeva N. Wax embedding technique of mounting anatomy museum specimens. MAMC J Med Sci 2016;2:131-3
| Introduction|| |
Anatomy museum is an indispensable part of a medical college since it gives complete knowledge of the human body in its four walls. It not just displays meticulously and painstakingly prepared prosections of different body parts and organs but also includes many other teaching aids. The exhibits can be wet specimens kept in preservative solution in glass or plastic jars and dry specimens such as bones, models, and charts. Among these, wet specimens are the most common in the anatomy museum.
Many soft specimens have to be mounted on supports such as glass or plastic sheets and plaster of Paris or else they can get flawed., Of these, use of glass or plastic sheets is very common. For this, glass sheet of suitable size is taken and the specimen is stitched on it using cotton thread or surgical suture.
This method is fine for little tougher tissues such as muscles and bones. However, in delicate tissues such as brain and pancreas, if stitches are too tight, they cut through the specimen, or if they become slack, the tissue hangs on the plate and gives a poor appearance. To avoid stitches, plaster of Paris has been used to mount the specimens. However, it gives the specimen a monotonous look. The high exothermic reaction that occurs when plaster of Paris is mixed with water can burn the skin. Some varieties of plaster of Paris contain powdered silica or asbestos which can cause silicosis or asbestosis, respectively. Individuals can be exposed in the workplace by breathing it in, eye contact, skin contact, and swallowing it.
To overcome all the above difficulties, Nim had used paraffin wax for mounting specimens. Due to shortage of cadavers, nowadays, importance is given on the utilization of prosected specimens to sustain teaching and learning of anatomy. Therefore, we have used this method of commonly available paraffin wax to mount the specimens and used it as an undergraduate teaching aid.
| Materials and Methods|| |
Various cut sections of the brain and heart procured from the dissection hall of the Anatomy Department of Maulana Azad Medical College were used for the procedure. They were washed thoroughly with normal saline. Other materials used were:
- Wooden blocks - four numbers
- Paraffin wax (melting point = 55°C-60°C)
- Glass or Perspex jar
- Preservative solution - 10% neutral buffered formalin.
The paraffin wax was melted just above its melting point (55°C-60°C) using an incubator. The wooden blocks were kept on a clean horizontal surface to form a rectangular mold of appropriate size (in relation to the specimen). Glycerin was applied on the inner surface of the wooden blocks and the horizontal surface. Molten wax was poured in that mold so that a layer of wax of about 0.5 cm thick is formed. When the wax started solidifying, the specimen was kept at the center of the mold with face up and then the wax was poured around the specimen till it anchored the specimen. It was allowed to cool gradually. Generally, it took 30-45 min to solidify at room temperature. When it had completely solidified, the blocks were removed and slowly lifted off the surface. The sides of the wax block were trimmed and smoothened using a scalpel. Then, it was kept in an appropriate-sized glass or Perspex jar, filled with the preservative solution (10% neutral buffered formalin) [Figure 1]a-e.
|Figure 1: Various sections of the human brain (a) mid-sagittal section of the brain, (b) ventral and dorsal aspect of the brainstem, and (c) transverse section of the cerebrum, wax mounted in Perspex jar; (d) transverse section of the cerebrum and (e) parasagittal section of the heart, wax mounted in glass jar|
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After mounting, the specimens were kept in the anatomy museum and asked for the views of the residents (10 number) of the anatomy department and 1st -year undergraduate students (150 number) regarding comparison between specimens mounted by this method and the specimens mounted by the older methods of plaster of Paris and glass sheets on various parameters such as cleanliness, contrast with background, acceptance of the method, comprehension, anatomical relations, and safety.
Precautions to be taken
- Dry the specimen before the procedure so that there is no film of water between the specimen and wax. This will improve anchorage of specimen with wax
- The wax should not be too hot so that specimen would not get damaged
- Wax should be allowed to cool gradually to prevent cracks in the wax.
| Results|| |
Majority of students (76.9%) considered wax embedding technique to be cleaner than the older methods. This method was more acceptable (55%) and comprehensive (79.4%) among the students. The anatomical details and background contrast of specimens was better appreciated in this method as compared to previous techniques. The students considered wax method to be safer (85%) than pervious techniques which used glasses and plaster of paris which students considered hazardous. The results are tabulated in [Table 1] and depicted in [Figure 2].
|Figure 2: Depicting the total responses of students and residents in percentage regarding comparison between specimens mounted by wax technique and the specimens mounted by the older techniques|
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|Table 1: Total responses (in percentage) of residents and 1st-year undergraduate students |
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| Discussion/Conclusion|| |
Wax mounting of specimens is cost-effective, easily reproducible, and less time-consuming. The materials needed are also easily available. This method is feasible, and in case of any error, the method can be repeated any number of times by simply melting the wax again. The mounted specimen is easy to handle and lightweight so that it can be easily transported. It is better for the delicate tissues as stitches are not used in this technique. The background contrast, cleanliness, and understanding of the anatomical relations were better than the older methods of plaster of Paris and glass sheets. The use of wax was also considered safer than plaster of Paris [Table 1] and [Figure 2].
These wax mounted specimens are displayed in the anatomy museum and used successfully for teaching undergraduate students in our department. A workshop on "Preservation Technique of Human Body - Embalming and Museology" was conducted by our department to train the postgraduate students and young faculties from all over India and to persuade them to pioneer this technique at their own institutes [Figure 3]a and b.
|Figure 3: (a and b) Demonstration of wax mounting technique during a workshop held at Maulana Azad Medical College|
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Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Pulvertaft RJ. Museum techniques; a review. J Clin Pathol 1950;3:1-23.
Jain LK, Babel H, Vijay N. New technique to mount specimen in the formalin filled jar for anatomy museum with almost invisible support. Int J Curr Res Rev 2013;5:45.
Mossman BT, Churg A. Mechanisms in the pathogenesis of asbestosis and silicosis. Am J Respir Crit Care Med 1998;157 (5 Pt 1):1666-80.
Nim VK. Wax mounting of specimen in anatomy museum. J Anat Soc India 2012;61:41-3.
[Figure 1], [Figure 2], [Figure 3]