Intermedia, Clearing Agents

Intermedia are chemicals used in microscopy to facilitate the transition between different solvents and processes. A specific category of intermedia are clearing agents, also called clearing agents. Clearing agents are used to make tissue samples more transparent, making them easier to visualize under the microscope.

Clearing agents are typically used after the fixation and dehydration of tissue samples. They replace the dehydrating solvents and remove any residual alcohol, making the tissue clearer and more translucent. This improves the penetration of the embedding and mounting media used in the following steps.

Some commonly used clearing agents are:

1. Xylene: Xylene is a common clearing agent that is often is used in histological laboratories. It has a high dissolving power and removes dehydrating agents such as alcohol from tissue.
2. Toluene: Toluene is another commonly used clearing agent that has similar properties to xylene. It is often used as an alternative to xylene depending on laboratory protocols and personal preferences.
3. Chlorobenzene: Chlorobenzene is a powerful clearing agent that is sometimes used for specific applications where higher tissue transparency is desired.

Clearing agents are usually used in a series of sequential steps, during which the tissue sample is immersed in the clearing agent and allowed sufficient time to remove the dehydrating solvents. After the clearing process, the tissue sample can be embedded in an embedding medium and cut into thin sections for microscopic analysis. The use of clearing agents in microscopy contributes to better visualization of tissue structures and helps researchers and pathologists to to conduct accurate observations and analyses. It provides a clearer and more transparent view of the tissue, which is essential for studying cell and tissue architecture and identifying specific cellular components.