Substitution of alcohol as the diluting solvent for formaldehyde results in which outcome?

• A. Better preservation of glycogen
• B. Faster processing time
• C. Increased tissue brittleness
• D. Reduced staining contrast

Answer: (A)

Using alcohol as the diluting solvent for formaldehyde changes the fixative environment from aqueous to more alcohol-rich, which helps keep water-soluble glycogen inside the tissue during fixation and the subsequent dehydration steps. Glycogen tends to be leached out when fixatives are water-based, so an alcohol-containing diluent reduces this loss and preserves glycogen better, making it more detectable with staining. The other potential effects aren’t the primary result here—processing time isn’t inherently accelerated by this solvent change, tissue brittleness or staining contrast aren’t the main outcomes in this context, whereas glycogen preservation is the most noticeable and technically relevant improvement.