5. Wash thoroughly in water.
6. Dehydrate in absolute alcohol.
7. Clear in xylol; mount in balsam.
Calcareous deposit black, as the result of the formation of phosphate of silver and its reduction by the action of light. Alum carmine may be used as a nuclear stain before the sections are treated with silver nitrate, or safranin may be used after the sodium sulphite has been washed out.
IV. CELL GRANULES AND CELL INCLUSIONS. The granules and cell-inclusions here included fall within the class of special protoplasmic structures found particularly in neoplasms and inflamed tissues, and which have been supposed to be parasites. For the staining of other cell-granules see Blood and Blood-forming organs.
1. Altmann’s Granules.
1. Fix small, thin pieces of fresh tissue in equal parts of 5 per cent potassium bichromate and 2 per cent perosmic acid for 24 hours. Wash in running water for several hours. After-harden in alcohol, and imbed in paraffin. Cut very thin and mount on cover-glass; remove paraffin.
2. Stain in aniline-water-acid-fuchsin (acid fuchsin 20 grms., aniline water 100 cc.), warming until vapor is given off.
3. When cool remove the fuchsin with a mixture of 1 part saturated alcoholic picric acid and 2 parts of water.
4. Renew the picric acid solution and warm on the paraffin oven for 30-60 seconds.