Under The Microscope: Histology Wax
Histology wax, also known as embedding or paraffin wax, is a crucial component in the preparation of tissue samples for microscopic examination in histology and pathology laboratories. It serves as a medium to support the tissue during the sectioning and staining process.
What Makes A Good Histology Wax?
But what makes a good histology wax? Here are several key characteristics that contribute to the quality of histology wax.
01. Melting point
Histology wax should have a specific melting point that allows easy infiltration of the tissue sample during the embedding process. The melting point should be low enough to prevent tissue damage but high enough to maintain the integrity of the sample during sectioning.
The ideal melting point for histology wax, also known as embedding or paraffin wax, is typically in the range of 56°C to 58°C (approximately 132°F to 136°F). This melting point provides a good balance between two essential factors in histology.
The specific melting point can vary slightly depending on the formulation of the histology wax and the specific requirements of the laboratory’s protocols and equipment. However, most histology laboratories prefer a melting point around 56°C to 58°C as it meets the necessary criteria for successful tissue embedding and sectioning.
02. Consistency and hardness
The wax should have a consistent texture and hardness to ensure uniform support for the tissue during sectioning. This allows for thin and precise slices to be obtained for microscopic examination.
A good histology wax should exhibit minimal shrinkage during the embedding and cooling process. Shrinkage can distort the tissue structure, affecting the accuracy of the histological analysis.
04. Low water content
Water can interfere with the infiltration of the wax into the tissue, leading to poor sectioning quality. High-quality histology wax should have low water content to facilitate proper infiltration and embedding.
Ideally, high-quality histology wax should have a water content below 0.5%. Water in the wax can interfere with the infiltration of the wax into the tissue during the embedding process.
Histology wax should be relatively transparent to allow for better visualization of the tissue during the sectioning and staining process.
06. Compatibility with stains
The wax should be compatible with various staining methods commonly used in histology. This ensures that the tissue retains its staining properties and allows for accurate identification and analysis of cellular structures.
07. Easy to handle
A good histology wax should be user-friendly and easy to manipulate during the embedding process. It should be moldable and capable of producing smooth blocks for sectioning.
Since histology wax comes into contact with biological specimens and laboratory personnel, it needs to be non-toxic and safe to use.
Paraffin wax is considered to be non-toxic when used as intended in histology and pathology laboratories. It is specifically formulated to be safe for use in the processing tissue samples for microscopic examination.
The primary components of histology wax are refined paraffin and other additives, which are chosen to meet the specific requirements of tissue embedding. These components are generally non-toxic and inert when handled properly. However, as with any laboratory reagent, it is essential to handle histology wax with standard laboratory safety practices to avoid potential hazards.
Overall, the quality of histology wax directly influences the accuracy and reliability of histological analysis. Laboratories often evaluate and select histology wax based on the specific needs of their protocols and equipment.