American Society for Clinical Pathology (ASCP) Histotechnologist Practice Test

What two stains are specifically used to demonstrate lipids in tissue?

1. Sudan black B and Oil red O

2. Hematoxylin and Eosin

3. Gram stain and Ziehl-Neelsen stain

4. Masson's trichrome and Giemsa stain

The correct answer is: Sudan black B and Oil red O

The correct answer is rooted in the specific properties of the stains used to identify lipids in tissue sections. Sudan black B and Oil red O are both lipid-specific stains that are widely used in histology to visualize fatty substances within tissues. Sudan black B stains neutral lipids and phospholipids, providing a strong contrast in various tissue samples. It appears as a deep black color against the background, making it easy to identify tissues with high lipid content. Oil red O, on the other hand, is a dye used to specifically stain triglycerides and lipids. It provides a vibrant red color to lipid-containing structures and is particularly effective in frozen sections. This dye requires the tissue to be preserved in a way that maintains the lipid integrity, allowing the oil red O to bind effectively. Using these two stains in conjunction enables pathologists and histotechnologists to effectively evaluate the presence and distribution of lipids in various tissues, which can be critical for diagnosing conditions such as atherosclerosis, steatosis, and various metabolic disorders.