Nonaqueous mounting media are also called anhydrous or organic mounting media. These are mounting media based on organic solvents, natural or synthetic resins dissolved in benzene, toluene or xylene. They are used to mount tissue sections after staining. These water-free mounting media protect the sample and provide optical brilliance of the dye. However, it is necessary to add a dehydration step to avoid the presence of water on the section that would interfere with the mounting medium.

Organic mounting media can only be used for enzymatic labels where the precipitate formed between the enzyme and the chromogen is not soluble in the organic solvents used during assembly.

There are permanent and non-permanent mounting environments. The anhydrous mounting media are generally permanent and thus are mounting media that can be used for the long-term storage of stained tissue sections.