Which statement about Mayer's hematoxylin used in routine histology is true?

• A. It is typically used progressively
• B. It is used only for special stains
• C. It stains cytoplasm blue
• D. It stains lipids

Answer: (A)

Mayer's hematoxylin is used as a routine nuclear stain and is typically applied in a progressive staining method. In progressive staining, the tissue is stained until the nuclei reach the desired blue/purple intensity, then rinsed and blueing steps follow to lock in the color. This makes it an efficient, standard approach for routine histology.

Understanding what it stains helps: hematoxylin targets nucleic acids, so nuclei appear blue or purple, while cytoplasm is usually counterstained pink by eosin. Lipids require different stains altogether, such as Sudan dyes, not hematoxylin. And Mayer's hematoxylin is not limited to special stains; it’s a common choice for routine hematoxylin-eosin staining workflows.

So the statement that it is typically used progressively best captures how Mayer's hematoxylin is commonly employed in everyday histology practice.