STAINING OF SIDEROCYTES (DEMONSTRATION OF PAPPENHEIMER BODIES)

STAINING OF SIDEROCYTES (DEMONSTRATION OF PAPPENHEIMER BODIES)

Siderocytes are red cells containing Pappenheimer bodies. Pappenheimer bodies are small, dense bodies of free iron, which can be demonstrated by a positive Prussian blue reaction'. Ferricyanide, under acidic conditions, reacts with iron to produce a blue colour. 

Staining solutions 

1. A. 1 % potassium ferricyanide

B. 0.2 N HCI Mix equal volumes of A and B just before use. 

2. 0.1 % aqueous safranin or eosin.

Specimen: Capillary blood or venous blood anticoagulated with EDTA.

Technique

(i) Prepare a thin blood smear. 

(ii) Fix it in methanol for 10 minutes. 

(iii). Dry the smear and keep it in the ferricyanide-HCI mixture for 10 minutes. 

(iv) Wash the smear in running tap water for 10 minutes and counterstain with aqueous safranin or eosin for 10-15 seconds. 

(v) Wash and dry, 

(vi) Examine under oil-immmersion objective. 

Interpretation The Pappenheimer bodies stain deep blue-black. They are less than 2 microns in diameter, unevenly distributed in the red cell (Fig. 4.4).

They are rarely seen in a normal blood specimen. They are found in disorders associated with impaired haemoglobin synthesis (e.g. thalassaemia), in lead poisoning, in some haemolytic conditions, or after splenectomy.