Trichrome

Question 1

Overall purpose of Masson Trichrome

Answer 1

Differentiate between smooth muscle (red) and collagen (blue/green) in tumors, and increased collagen in cirrhosis

Question 2

What do these three components stain as in Masson Trichrome: Nuclei, Collagen, Muscle

Answer 2

Nuclei: Grey to Black
Collagen: Blue to Green
Muscle: Red (includes keratin, RBCs, cytoplasm)

Question 3

Purpose of biebrich scarlet and acid fuchsin?

Answer 3

Stains acidophilic components red

Question 4

Purpose of phosphomolybdic/phosphotungstic acid?

Answer 4

“Bumps” red dye out of larger tissue pore (eg. collagen) and acts as a mordant for subsequent dyes

Question 5

Purpose of aniline blue?

Answer 5

Large dye molecule that stains collagen (and other loose connective tissue) dark blue

Question 6

What causes a decrease in red stain of Masson Trichrome?

Answer 6

Old/Overused Biebrich Scarlet/Acid Fuchsin - make fresh again

Question 7

What causes a decrease in blue stain of Masson Trichrome?

Answer 7

Prolonged rise following PMA/PTA, old/overused aniline blue, over differentiated with acetic acid following staining.

Question 8

What causes a decrease in all staining?

Answer 8

Failure to pre-mordant with Bouin’s fluid when using formalin fixed tissue

Question 9

What is the purpose in premordant in Bouin’s Fluid?

Answer 9

Picric acid acts as mordant for anionic dyes used in acidic conditions, like trichrome dyes.