Special Stains and Histochemistry Flashcards
6 cards from real ASCP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Special Stains and Histochemistry flashcards as text
The Alcian blue stain at pH 2.5 is used to identify what type of tissue component?
Answer: Acid mucopolysaccharides (acid mucins)
Alcian blue at pH 2.5 stains both sulfated and carboxylated (acid) mucopolysaccharides blue, distinguishing them from neutral mucins.
In the Gram stain used in histology (Brown and Brenn technique), how do gram-positive bacteria appear?
Answer: Blue-black
Gram-positive bacteria retain the crystal violet-iodine complex after decolorization and appear blue-black in the Brown and Brenn tissue Gram stain.
Which special stain is used to highlight elastic fibers in tissue sections?
Answer: Verhoeff's iron hematoxylin (VVG) or Weigert's resorcinol-fuchsin
Verhoeff-Van Gieson (VVG) stain colors elastic fibers blue-black, collagen red, and other tissue elements yellow.
What is the purpose of the mucicarmine stain in histopathology?
Answer: Highlight acid and neutral mucins, especially useful for Cryptococcus
Mucicarmine stains mucin deep rose-red and is particularly useful for identifying the mucoid capsule of Cryptococcus neoformans.
In the Ziehl-Neelsen (acid-fast) stain, what color do acid-fast organisms (e.g., Mycobacterium tuberculosis) appear?
Answer: Bright red/carmine
Acid-fast organisms retain the carbol-fuchsin primary stain after acid-alcohol decolorization and appear bright red against a blue background.
What color does reticulin stain (Gordon and Sweet silver method) produce for reticular fibers?
Answer: Black
The silver impregnation method deposits metallic silver on reticulin (type III collagen) fibers, staining them black against a golden-brown background.