Infiltration of Tissue in Histopathology Lab

 Infiltration of Tissue in Histopathology Lab

The final stages are called ‘infiltration’ and ‘blocking out’. Infiltration is when the final xylene is replaced with molten wax, which infiltrates the tissue. Again, this is typically three different wax immersions to ensure that none of the clearing agent remains in the tissue.

After the final infiltration, the tissue cassettes are transferred to an embedding station. This machine has reservoirs of molten wax, hotplates, and a cold plate for setting the tissue blocks.

The infiltrated tissue is removed from the cassette and orientated within a suitably sized metal mold. The mold is filled with molten wax, the main part of the labeled cassette is placed on top, and this is also filled with wax. The whole mold is transferred to the cold plate to finally set.

That ends the journey from tissue to wax block, which is, I guess, the start of another journey of sectioning, making slides, and immunohistochemistry!

Finally, below is a table that highlights the typical main stages of tissue processing for histology.

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