a. Connective-tissue Fibrils. The demonstration of connective-tissue fibrillæ or reticulum is of great importance in the differential diagnosis of sarcoma and carcinoma. Van Gieson’s method is the best stain for the coarser fibrils, but does not bring out the finer reticulum as well as Mallory’s aniline-blue method.
1. Mallory’s Reticulum Stain.
1. Fix in mercuric chloride or Zenker’s. After-harden in alcohol; imbed in celloidin or paraffin; cut.
2. Stain in 1/10 aqueous acid fuchsin 5-10 minutes.
3. Transfer directly to the following solution and stain for 20 minutes or longer:—
| Aniline-blue, water-soluble (Grübler) | 0.5 | grm. |
| Orange G (Grübler) | 2.0 | grms. |
| 1 per cent aqueous solution of phosphomolybdic acid | 100 | cc. |
4. Wash and dehydrate in several changes of 95 per cent alcohol; dry with absorbent paper.
5. Clear in xylol or origanum oil.
6. Mount in balsam.
Fibrils and reticulum of connective tissue, amyloid, mucin and connective-tissue hyalin are blue; nuclei, protoplasm, fibroglia fibres, axis cylinders, neuroglia fibres and fibrin are red; elastic fibres are pink or yellow; red blood-cells and myelin-sheaths are yellow.