CHAPTER II 

 SPECIAL STAINING METHODS 



Of these only the more common will be described. 



(i) Silver-nitrate Method of Staining Intercellular Sub- 

 stance. — After first washing, the tissue, e.g., omentum or cornea, 

 is placed in a from 0.2- to i-per-cent. solution of silver nitrate, or 

 better, protargol, where it is kept in the dark for a half-hour or more 

 according to the thickness and density of the tissue. The specimen 

 is then washed in water, transferred to 40-per-cent. alcohol and placed 

 in the direct sunlight until it assumes a light brown color. It is then 

 placed in fresh 80-per-cent. alcohol for preservation. 



(2) Chlorid of gold in i-per-cent. aqueous solution is used in 

 the same manner for demonstrating connective-tissue cells and their 

 finer processes. 



(3) Weigert's Elastic-tissue Stain. — This is prepared as 

 follows : 



Fuchsin, 2 gm. 



Resorcin, 4 gm. 



Water, 200 c.c. 



These are boiled for live minutes, during which 25 c.c. of liquor ferri 

 sesquichlorati are stirred in. The result is a precipitate which should 

 be filtered out after the liquid has become cool. After drying, 200 

 c.c. of 95-per-cent. alcohol are added to the filtrate and boiled until 

 the latter dissolves. Lastly, 4 c.c. of hydric chlorid are added to 

 the solution. Sections should remain in the stain thirty minutes, 

 after which they are washed in alcohol until the stain ceases to be 

 given off. 



(4) Verhoeff's Differential Elastic Tissue Stain. — 



• Haematoxylin crystals (Griibler), 0.15 gm. 



Absolute alcohol, 25.00 c.c. 



Dissolve by heating, then add 5-per-cent. aqueous solution 

 ammonium hydrate, i drop. Allow to stand 5 minutes or 

 longer, then add Lugol's solution (iodin 2 parts, potassium, 

 iodid 4 parts), 22.00 c.c. 



Filter, let stand in corked bottle 24 hours. 



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