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MICROWAVE CHURUKIAN-SCHENK ARGYROPHIL METHOD
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FIXATION: 10% buffered neutral formalin.
TECHNIQUE: Paraffin sections cut at 5 μm.
SOLUTIONS:
Citric Acid – Sodium Citrate Solution (Stock)
Citric acid, monohydrate ------------------------------------------------------- 0.2 gm
Sodium citrate, dihydrate ------------------------------------------------------ 0.2 gm
Distilled water ------------------------------------------------------------------ 100.0 ml
The pH of this solution is approximately 3.8. Store in a refrigerator at 3-6o C.
Citric Acid – Sodium Citrate Solution (Working)
Citric acid – sodium citrate (stock) ---------------------------------------------- 1.5 ml
Distilled water ------------------------------------------------------------------ 150.0 ml
The pH of this solution is approximately 3.8.
0.5% Silver Nitrate Solution
Silver nitrate -------------------------------------------------------------------- 0.2 gm
Citrate acid – sodium citrate, working solution ----------------------------- ---- 40.0 ml
Prepare fresh.
Bodian’s Developer
Sodium sulfite (anhydrous) ---------------------------------------------------- 2.0 gm
Hydroquinone ------------------------------------------------------------------ 0.4 gm
Distilled water ------------------------------------------------------------------ 40.0 ml
Prepare fresh.
0.1% Nuclear Fast Red (Kernechtrot Solution)
Dissolve 0.1 gm nuclear fast red in 100 ml of 5% solution of aluminum
sulfate with the aid of heat. Cool, filter, and add a few grains of thymol
as a preservative.
Neuroendocrine cell granules (argentaffin and argyrophil) in various organs stain dark brown to black. Nuclei are orange to red the background a light yellow-orange.
Argyrophil cells are found in the gastrointestinal mucosa, pancreas, trachea, bronchi, prostate and ovary. Tumors derived from these cells are called apudomas or neuroendocrine tumors. Argyrophil cells, as their names indicates, have an affinity for silver ions but lack the ability to convert the silver ions to the metallic state. This is why a reducing agent is needed in the staining procedure.
In Pascual’s method and our modification of Pascual’s method, tissue sections are double impregnated with silver nitrate followed by treatment with a reducing solution. In the described staining method a triple treatment with silver nitrate and the reducing solution is necessary in order to obtain optimal staining results.
In our modification of Pascual’s argyrophil method, the pH of the distilled water is adjusted to 4.2 with dilute aqueous citric acid. This requires the use of a pH meter and is somewhat time consuming. The described method utilizes a citric acid – sodium citrate buffer with a pH of 3.8 that is easy to prepare. Like most buffer solutions ours is stable when stored in a refrigerator at 3-6o C.
The shelf-life of silver nitrate and hydroquinone can be greatly increased by storing the reagents in a refrigerator at 3-6° C
The use of a microwave oven, plus other modifications, reduces the staining time by more than one hour and thirty minutes from our original method without compromising the quality of the staining results.
Brinn, N.T.: Rapid metallic histologic staining using the microwave oven. J. Histotechnol. 6:125-129, 1983.
Churukian, C.J. and Schenk, E.A.: A modification of Pascual’s argyrophil method. J. Histotechnol. 2:102-103, 1979.
Pascual, J.S.: A new method for easy demonstration or argyrophil cells. Stain Technol. 51:231-235, 1976.
Smith, D.M. and Haggitt, R.C.: A comparative study of generic stains for carcinoid secretory granules. Amer. J. Surg. Pathol. 7:61-68, 1983.
Churukian, C.J.: Microwave modification of Pascual’s argyrophil method. Histologic 19:121-123, 1989.
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Diagnostic Application: