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Colloidal iron stain

Colloidal Iron: Staining Protocol

Sample Type Required: Deparaffinized and re-hydrated tissue sections on positively charged slides.

Fixative:10% Neutral Buffered Formalin




Technical Notes


12% Acetic Acid Solution

Brief Rinse


Working Colloidal Iron Solution

(10mL Stock Colloidal Iron, 18mL Distilled Water and 12mL Glacial Acetic Acid)

1 Hour

Stock Colloidal Iron can be purchased commercially.


12% Acetic Acid Solution

3 Changes x 3 Minutes Each


Ferrocyanide-Hydrochloric Acid Solution

(25mL Potassium Ferrocyanide, 2% and 25mL Hydrochloric Acid, 2%)

20 Minutes


Running Tap Water

5 Minutes


Nuclear Fast Red Solution

5 Minutes


Running Tap Water

1 Minute

Clouding will result when slides are placed in the alcohols if slides are not washed well after Nuclear Fast Red staining.

Expected Results

  • Acid Mucins and Sialomucins = Deep Blue
  • Nuclei = Pink to Red
  • Cytoplasm = Pink

Post Staining Procedure:

 • Tissue sections must be counterstained to fully recognize the presence of positive staining. This can be achieved with the use of  nuclear fast red, which provides a pink background.
• After counterstain, tissue sections should be rinsed well in distilled water, dehydrated with 95% alcohol, followed by 100% alcohols, cleared with xylene (or xylene substitute), and cover-slipped.