The 1% acetic acid solution is a dilute form of acetic acid used specifically for histological applications. In histology, it is used to differentiate stains by removing excess dyes that have non-specifically bound to the tissue. This allows clearer visualization of the specifically stained structures.

In addition, the 1% acetic acid solution is used to rinse tissue sections after staining to remove excess dye and avoid possible color transfer between adjacent sections.
Another important use of dilute acetic acid is to gently transfer tissue sections to the acidic environment of the staining solution. This can help ensure optimal staining of structures, as many staining processes in histology are pH-dependent.