45 



A stain of quite general usefulness. The collaginous connective tissue fibers,, 

 reticular tissue, cartilage, osseous tissue, mucus, etc., are stained blue; nuclei,, 

 cytoplasm, muscle, red; red blood corpuscles, orange. 



121. Light Green. An acid stain sometimes useful as a counterstain with 

 safranin. A 0.2% alcoholic solution may be used in the differentiation of the 

 latter stain. 



122. Acid Violet may be used in similar cases and in the same manner^ 



123. Bleu de Lyon (Lyons' Blue). A plasma stain frequently useful as a 

 counter stain after safranin or carmine (in toto). Employ an alcoholic (95%) 

 solution of about half saturation and stain sections for 10 to 15 minutes or longer. 

 Rinse with 95% alcohol and dehydrate more or less rapidly depending on the 

 differentiation desired. 



124. Iodine. In addition to a certain value as a fixer and to facilitate the 

 removal of mercuric chlorid from tissue, usefulness as a differentiator after basic 

 aniline dyes, iodine has a place among the stains for the differential coloring of 

 starch, glycogen, amyloid, cellulose, etc. The following solutions may be men- 

 tioned: (a) saturated aqueous solution; (b) Iodine-potassium iodid solutions. 

 (Gram's, Lugols), iodine 1 gram, potassium iodid 2 grams, distilled water 300 c. c 

 Lugol's solution is six times as strong, (c) 10% alcoholic solution, (tincture); 

 (d) for a formula useful for staining glycogen, amyloid, etc., see 229. 



125. Resorcinfuchsin (Weigert). Prepare a concentrated solution of 

 the dry powder in a 1% solution of hydrochloric acid in 95% alcohol. Designed 

 for staining differentially elastic connective tissue fibers. 



Stain sections 15 to 30 minutes, wash and dehydrate in 95% and absolute 

 alcohol, clear in xylene, mount in balsam. 



The stain may be directly prepared according to a modified formula of Weigert,, 

 Formula: Fuchsin (basic), 2 grams; resorcin, 4 grams; water, 200 c. c. Boil 

 several minutes (10 or more); add 25 c. c. 30% solution ferric chlorid and boil 

 5 or 10 minutes longer. If the stain is not all precipitated, more of the ferric 

 chlorid solution may be added. Permit the liquid to cool. Let the precipitate 

 settle and decant fluid, or filter. Dissolve precipitate in 200 c. c. 95% alcohol, 

 employing heat if desired (boiling on a water bath). Filter. When the filtrate 

 is cool, add 4 c. c. strong hydrochloric acid. 



The stain may be followed by picro-fuchsin or other similar reagent for stain- 

 ing the white connective tissue fibers. 



126. Orcein (Taenzer-Unna). Another standard method of staining 

 the elastic connective tissue fibers (elastin). Formula: Orcein D., 1 gram;: 

 95% alcohol, 100 c. c.; strong hydrochloric acid, 1 c. c. 



Stain sections ]/2 to 1 hour, wash and differentiate in 95% alcohol and acid 

 alcohol ( 82). Elastin stained dark brown. Other differential stains may be 

 used on the same preparation. 



127. Verhoeff's Elastin stain. [44] Formula: Hematoxylin, 0.15 grams;. 

 Absolute alcohol, 25 c. c.; dissolve by heat and add 1 drop of 5% ammonia solu- 

 tion. Permit it to stand for at least 5 minutes and add Lugol's solution ( 124),. 

 22 c. c. ; filter and permit it to stand for 24 hours in a corked bottle. The solution 

 remains good for about 3 months. For use, add a 7% ale. sol. ferric chlorid, 1 

 drop per c. c. 



