Prussian Blue Staining Pathology Quiz

Nuclear fast red is commonly used as a counterstain after Perls staining. It provides a red-pink background that contrasts well with blue iron deposits, improving tissue interpretation.

In a positive Perls stain, ferric iron reacts to form Prussian blue pigment. This appears as blue to blue-green granules within cells or extracellular spaces. Other colors such as red, black, or yellow-brown correspond to different pigments or staining methods.

Standard Perls staining detects ferric iron rather than ferrous iron. It does not reliably stain iron bound within hemoglobin. The stain is especially useful for identifying hemosiderin, which contains ferric iron stored in tissues after blood breakdown.

Hemosiderin-laden macrophages stain strongly with Perls because hemosiderin contains ferric iron. These cells commonly appear in areas of prior bleeding or iron overload. Other tissue components such as mucin or amyloid require different special stains.

Coarse blue granules in macrophages near old hemorrhage represent hemosiderin. This indicates prior bleeding with iron storage in macrophages, distinguishing it from calcification or other pigments.

Perls Prussian Blue stain specifically detects ferric iron stored in tissues, most commonly as hemosiderin. It does not stain calcium, glycogen, or collagen. The reaction forms an insoluble blue pigment when ferric iron reacts with potassium ferrocyanide, allowing iron deposits to be easily identified microscopically.

Potassium ferrocyanide and hydrochloric acid are essential reagents in the Perls reaction. The acid releases ferric ions from proteins, allowing them to react with ferrocyanide and form the characteristic blue pigment seen in positive staining.

Old hemorrhage or chronic bleeding leads to red blood cell breakdown, releasing iron that becomes stored as hemosiderin. This stored iron accumulates over time and is readily detected by Perls staining.

In bone marrow, Perls staining is used to assess iron stores and identify sideroblasts. Ring sideroblasts show iron-loaded mitochondria and are important in diagnosing certain anemias.

The liver is the primary organ evaluated for iron overload using Perls stain. It is a major iron storage site and is commonly biopsied in suspected hemochromatosis or transfusion-related iron excess.

Prolonged acidic decalcification can dissolve iron from tissue sections, leading to false-negative Perls results. Careful specimen processing is essential to preserve stainable iron.

Acid in the Perls reaction releases ferric ions from protein complexes. This step is necessary so ferric iron can react with ferrocyanide to form the visible blue pigment.

In many iron overload conditions, hepatocytes near portal tracts show iron deposition early. This periportal pattern helps distinguish different causes of iron accumulation.

Perls staining distinguishes iron pigment from other brown pigments seen on routine stains. Hemosiderin may appear brown on H&E, but Perls confirms its identity by turning it blue.

A strong positive Perls stain in splenic macrophages indicates increased hemosiderin consistent with iron accumulation. This finding is common in hemolysis, transfusions, and chronic blood breakdown.