Which staining method is used to demonstrate cross striations?

• A. Phosphotungstic acid-hematoxylin
• B. Masson Trichrome
• C. Verhoeff-van Gieson
• D. Oil Red O

Answer: (A)

Cross striations are the repeating sarcomeric bands visible in striated muscle fibers. To emphasize that pattern under light microscopy, a stain that highlights myofibrillar structures is used. Phosphotungstic acid-hematoxylin binds to muscle proteins and accentuates the alternating dark and light bands, making the cross-striated pattern stand out clearly. This staining choice specifically reveals the organized sarcomere structure, which is why it’s the best option for demonstrating cross striations.

The other stains serve different purposes: Masson Trichrome highlights connective tissue and muscle in contrasting colors but does not emphasize the cross-striation pattern; Verhoeff-van Gieson targets elastic fibers; Oil Red O stains lipids in frozen tissue sections.