The composition of the aqueous mounting media is based on distilled water. They are used to mount tissue sections directly after staining when the dye used is soluble in alcohol, xylene or other organic solvents such as most lipid dyes.

There are 3 main types of aqueous mounting media: syrups, gelatin-based media and gum arabic media.

 

It is advisable to use aqueous mounting media when using chromogenic substrates of HRP and alkaline phosphatase (such as AEC, DAB, BCIP / NBT) whose colored precipitates are soluble in organic solvents, slices therefore, tissue can not be dehydrated as required by the use of anhydrous mounting media.

There are permanent and non-permanent mounting media. Permanent mounting media are mounting media that can be used for the long-term storage of stained tissue sections.