Gomori's Aldehyde Fuschsin

Classification: connective tissue stain

Mechanism of staining: ionic bonding/van der Waals forces

Purpose: stain elastin, beta cells in Islets of Langerhans, basophils in anterior pituitary, and mast cells

Control tissue: aorta, skin, lung, internal control

Properly Stained Slide

Elastin fibers: Royal purple

Muscle, cytoplasm, collagen: Green

 Nuclei: Not demonstrated


REAGENT

REAGENT

PURPOSE

MECHANISM OF STAINING

SOURCE OF ERROR

Lugol’s iodine

Oxidizer

Creates reactive groups in apolar elastin

Omitted: Elastin is less intense. Oxidization is optional.

Too short: Elastin is less intense.

Too long: No problem.

Sodium thiosulphate (hypo)

Removes iodine discoloration

 

Omitted: Background discoloration will occur.

Too short: Nuclei and cytoplasm will not be demonstrated or weakly stained.

Too long: No problem.

Aldehyde fuchsin

Primary stain (progressive stain)

 

o      Pararosanilin (Basic Fuchsin) 

o      70% ethanol 

o      HCl

o      Fresh Paraldehyde

H bonding/ van der Waals bonding to the apolar core of elastin fibers. Salt linkages to the microbrillar components of elastin.

Omitted: Elastin not demonstrated.

Too long: : Fine elastin fibers not demonstrated.

Too short: Fine elastin fibers not demonstrated.

95% Alcohol rinse

 

 

Omitted: Aldehyde fuchsin precipitation.

Too long: Fine elastin fibers are not demonstrated.

Too short: Fine elastin fibers are not demonstrated.

Light green

Counterstain

 

Omitted: No other tissue components demonstrated.

Too long: Fine elastin fibres obscured.

Too short: Other tissues stain lightly and no detail seen.

 

 

Properly Stained Slide

Close up detail of the finely stained royal purple elastin fibers in thin skin.


References

Officer B. HIML251 Lecture notes: Elastic Stains: Verhoeff’s van Gieson & Gomori’s Aldehyde Fuchsin, January 21, 2009