Embedding / Casting

The embedding process typically follows tissue processing steps such as fixation, dehydration, and clearing. Once the tissue samples have been adequately processed, they are ready for embedding. 

This is the next step after tissue processing, also known as wax embedding and preparing tissue blocks. Embedding means casting or blocking, the specimen are enclosed in an embedding medium sing a mould. In this process, the tissue transferred from the final wax bath (in thissue processor) and is placed ina mould filled with warm liquid /moulten paraffin (impregnated with wax), on cooling this forms a slod paraffin block.

Here's an overview of the embedding process:

• Infiltration with Embedding Medium: The dehydrated and cleared tissue specimens are immersed in melted paraffin wax, which acts as the embedding medium. The tissue samples are placed in small containers called embedding molds or cassettes.

• Orientation: Proper orientation of the tissue samples within the embedding molds is crucial to ensure that the resulting tissue sections on microscope slides accurately represent the original tissue architecture. Orientation marks or tissue cassettes with embedding molds may be used to ensure consistent orientation.

• Embedding Molds: The tissue specimens, along with the embedding medium, are poured into embedding molds or cassettes, and the molds are allowed to cool and solidify. This process results in the formation of wax blocks containing the tissue specimens embedded within.

• Trimming: After the wax has solidified, the embedded tissue blocks are removed from the molds and trimmed to remove excess wax and achieve a uniform size and shape.

• Sectioning: The trimmed tissue blocks are mounted onto a microtome, which is a specialized cutting instrument used to produce thin tissue sections. The microtome allows the tissue blocks to be sliced into thin sections of consistent thickness, typically ranging from 5 to 7 micrometers.

• Mounting: The thin tissue sections are then mounted onto glass microscope slides, where they are ready for staining and microscopic examination.

Embedding ensures that tissue samples are adequately supported and preserved during the sectioning process, allowing for the production of thin, uniform sections suitable for microscopic examination. The resulting tissue sections can then be stained using various histological stains to highlight specific cellular structures and pathological changes, enabling pathologists to make accurate diagnoses and provide valuable insights into disease processes.

View other equipment details:

Grossing station || Tissue processing