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Iron stain is a vital technique used in the examination of bone marrow smears. It permits us to picture iron stores inside cells and tissues, giving fundamental bits of knowledge about different ailments. In this blog, we’ll dive into the standards behind iron staining, the parts expected for the staining methodology, the means in question, and the understanding of the results.
Principle of Iron Stain
The iron found in bone marrow is stored in various forms, such as hemosiderin within tissue macrophages and synthetic hemoglobin within red blood cells. These iron deposits play crucial roles in blood cell production and function. Iron staining involves the use of specific reagents to detect and visualize these iron deposits. The staining reaction, known as the Prussian blue iron reaction, results in the formation of blue ferrocyanide iron precipitates.
To perform iron stain, you’ll need several key components:
- Fixative: Formaldehyde is used to preserve the cellular structure of bone marrow smears.
- Potassium Ferrocyanide Arrangement (Arrangement A): This arrangement contains potassium ferrocyanide, a basic reagent for the Prussian blue response.
- Hydrochloric Corrosive Arrangement (Arrangement B): Hydrochloric corrosive is utilized to make suitable circumstances for the staining response.
- Safranin Solution (Solution C): Safranin is used as a counterstain to enhance the visualization of iron deposits.
Fresh bone marrow cell smears are required for the staining procedure.
Follow these steps to perform the iron staining procedure:
A. Working Solution Preparation:
- Dip Stain Working Solution:
- Mix 20 ml of Solution A and 20 ml of Solution B in a dye vat (for a 50 ml volume dyeing vat). This solution can be used for 8-10 smears.
- Drops Stain Working Solution:
- Mix 1 ml of Solution A and 1 ml of Solution B in a test tube.
B. Staining Procedure:
- Fix bone marrow smears using formaldehyde for 30 to 60 seconds, then rinse with distilled water and allow to air dry.
- Apply the working solution to the smears either by dropping or dipping:
- For dip staining: Submerge the slides in the dip stain working solution for 60 minutes. Rinse with distilled water and dry.
- For drops staining: Apply the drops stain working solution to the slides, then rinse and dry.
- Counterstain the smears with Solution C for 1-2 minutes. Rinse with distilled water and dry.
Iron deposits will appear as blue granules, small deposits, or masses. The interpretation involves assessing both extracellular and intracellular iron:
- Negative (-): No blue iron granules.
- Positive (+): Few iron granules or deposits.
- 2+: Numerous iron granules and deposits.
- 3+: Lots of iron granules or deposits and a few small masses.
- 4+: Abundant iron granules, deposits, and many small masses.
- Calculate the percentage of nucleated erythrocytes with positive blue granules in the cytoplasm. Positive cells typically contain 1-2 small and irregular iron granules. Rarely, more than 5 iron granules are found.
You can find more information about iron staining in clinical laboratory methods and diagnosis references, including “Gradwohl’s Clinical Laboratory Methods And Diagnosis, 8th Edition.”
Iron stain is a crucial technique in the examination of bone marrow smears. By carefully preparing and applying the staining solutions, medical professionals can visualize and interpret iron deposits, contributing to diagnosing and understanding various medical conditions related to blood cell production and iron metabolism.