1. Fix in osmic acid, mercuric chloride or other fixative.
2. Stain sections by placing them in liq. ferri. sulfur. oxyd. (Germ. Pharm.) diluted with double its volume of water, for 24 hours; wash carefully in distilled water and then in tap water; stain in 1 per cent watery hæmatoxylin until section is black. Wash in water. Differentiate in 10-30 per cent acetic acid, or in liq. ferri. sulfur. oxyd. diluted with distilled water 1-20. A 10 per cent solution of ferric sulphate may be used instead of the persulphate.
4. Heidenhain’s Iron-Haematoxylin.
1. Imbed in paraffin after fixation in mercuric chloride.
2. Immerse section in a 1.5 per cent solution of iron-alum sulphate (violet-colored salt) or iron-ammonium sulphate for ½-3 hours.
3. Wash in water.
4. Stain in 0.5 per cent watery hæmatoxylin or hæmatein for 12-18 hours.
5. Wash in water.
6. Differentiate in the iron-alum or iron-ammonium solution until the section becomes deep blue (control under microscope) and nuclear structures stand out distinctly.
7. Wash in running water for 15 minutes.