After completing Masson's Trichrome technique, you notice your control slide doesn't have nuclei stained. What is the reason for this?

• A. Used Aluminum hematoxylin to stain nuclei
• B. Used Iron hematoxylin
• C. Over-dehydration of slides
• D. Not enough hematoxylin

Answer: (A)

Masson's Trichrome needs a nuclear stain that stays visible through the rest of the staining steps. Aluminum hematoxylin, while it can stain nuclei, does not hold up as well as iron-containing hematoxylin in this protocol and often fades or fails to produce strong nuclear coloration after differentiation and counterstaining. That’s why the control slide can look like it has no nuclei when aluminum hematoxylin is used. Using a traditional nuclear stain such as iron hematoxylin (Weigert’s) will give dark, persistent nuclei that remain visible after the subsequent steps.