What is Mounting in Histology?
Mounting is a critical step in histology where a stained tissue section is placed on a microscope slide and covered with a coverslip for examination. This process is essential for preserving the tissue and ensuring it can be viewed clearly under a microscope.
Common Mounting Errors
Several errors can occur during the mounting process, which can impact the quality of the histological examination. Some of these errors include:Air Bubbles
Air bubbles are one of the most frequent mounting errors. They occur when air gets trapped between the tissue section and the coverslip. These bubbles can obscure important details in the tissue, making it difficult to interpret the slide accurately. To avoid air bubbles, ensure that the mounting medium spreads evenly across the slide.Improper Drying
Improper drying of the tissue section before mounting can lead to various issues. If the section is not completely dry, it can cause the mounting medium to spread unevenly, resulting in distortions. Additionally, residual moisture can lead to the formation of air bubbles and interfere with the adhesion of the coverslip.Incorrect Mounting Medium
Using the wrong
mounting medium can affect the clarity and preservation of the tissue. Some mounting media are suitable for specific types of stains, while others are not. For instance, aqueous mounting media are often used for water-soluble stains, whereas resinous media are used for non-aqueous stains. Choosing the appropriate mounting medium is crucial for maintaining the integrity of the stained tissue.
Cover Glass Placement
Incorrect placement of the
cover glass can cause several issues. If the coverslip is placed at an angle or with excessive pressure, it can distort the tissue section. Additionally, if the coverslip is not properly centered, parts of the tissue may be excluded from the field of view under the microscope.
Excess Mounting Medium
Using too much
mounting medium can lead to overflow around the edges of the coverslip. This overflow can harden and create a barrier, trapping air bubbles and debris. It can also make the slide difficult to handle and store. To avoid this, use just enough mounting medium to cover the tissue section without excess.
Contamination
Contamination is another common error during the mounting process. Dust, lint, and other particulates can become trapped between the tissue section and the coverslip. This can obscure the tissue and lead to misinterpretation. Keeping the workspace clean and using
sterile techniques can help minimize contamination.
Mechanical Damage
Handling errors can lead to mechanical damage to the tissue section. If the slide or coverslip is handled too roughly, it can cause tears or folds in the tissue. Additionally, using inappropriate tools or techniques to place the coverslip can damage the tissue. Gentle handling and the use of proper tools are essential to prevent mechanical damage.How to Avoid Mounting Errors
Avoiding mounting errors involves careful attention to detail and adherence to best practices. Here are some tips: Ensure the tissue section is completely dry before applying the mounting medium.
Choose the appropriate mounting medium for the specific stain used.
Apply the mounting medium evenly and in the right amount to avoid air bubbles and overflow.
Place the coverslip gently and ensure it is properly centered.
Maintain a clean workspace to prevent contamination.
Handle slides and coverslips with care to avoid mechanical damage.
Conclusion
Mounting is a crucial step in the preparation of histological slides. Understanding and avoiding common mounting errors can significantly enhance the quality of histological examinations. By following best practices and maintaining attention to detail, one can ensure that the tissue sections are preserved and clearly visible under the microscope.
