Bouin's solution is composed of picric acid, formaldehyde and acetic acid. The main use of Bouin's fluid is the fixation of lymph nodes, prostate and kidneys biopsies. It is a very good fixative when soft and delicate tissue structures must be preserved on the other hand it is not advisable to use it to fix the tissues for electron microscopy.

Bouin solution can also be used for decalcifying bones when supplemented with formic acid. The addition of 25% ethanol makes it possible to use the Bouin fluid for the tissues rich in adipose like the breast.

Bouin's liquid colors the tissues in yellow, but this staining can be eliminated with washings with ethanol or PBS-Tween.

Bouin's liquid should not be used for RNA detection because this fixative damages the nucleic acids.

If you wish to study the blood cells, it is advised not to use the Bouin fluid because it destroys these cells, it is preferable to use paraformaldehyde.