Which of the following is NOT listed as an 'other glycogen fixative'?

• A. Bouins
• B. 80% alcohol
• C. alcoholic formalin
• D. acetic alcohol formalin

Answer: (A)

Glycogen is soluble in water and can be leached out during tissue processing, so certain fixatives are preferred because they preserve carbohydrates without removing them or interfering with carbohydrate staining. In lists of “other glycogen fixatives,” fixatives that are specifically noted for preserving glycogen include alcohol-containing or alcohol-formalin mixtures that balance fixation with carbohydrate retention.

Bouin's solution contains picric acid, formaldehyde, and acetic acid. While it fixes many tissue components well, its picric acid component can cause staining interference and, in some protocols, extraction or alteration of glycogen, so it isn’t typically listed as an “other glycogen fixative.” That’s why it stands out as not being listed in that category. The other options—such as alcohol-containing fixatives—are the ones commonly cited as glycogen-preserving fixatives in reference materials.