Stain with hæmatoxylin, and after washing use a 1 per cent water solution of orange G, staining ¼-3 hours. Treat otherwise as for eosin-staining.
e. Carmine and Picric Acid.
Stain with borax- or lithium-carmine; differentiate in acid alcohol and wash thoroughly. Then counterstain with picric acid, as for hæmatoxylin and picric acid. Carmine and picric acid may also be combined in one stain, as picro-carmine, but this is rarely used at the present.
f. Eosin and Methylene-blue.
(For tissues fixed in mercuric chloride or Zenker’s.)
1. Stain in a 5-10 per cent aqueous eosin for 20 minutes or longer, until a deep eosin-stain is obtained.
2. Wash out excess of eosin in water.
3. Stain in Unna’s alkaline methylene-blue, diluted 1-4 or 5 with water, 10-15 minutes.
4. Wash in water.
5. Differentiate in 95 per cent alcohol, keeping the section in constant motion to obtain a uniform decolorization. Control process under microscope. Wolbach advises the use of a 0.75-1.5 per cent solution of colophonium in methyl alcohol as a differentiating medium instead of 95 per cent alcohol. For tissues fixed in formol or alcohol a 10 per cent solution should be used.