SINGLE STAINS WITH NUCLEAR DYES 657 



Delafield's Hematoxylin : 



Hematoxylin 4 grm. 



95 per cent, alcohol 25 cc. 



Saturated aqueous solution of ammonium 



alum 400 cc. 



Mix as above and permit the fluid to stand exposed to the air 

 and sunlight for three or four days. Add : 



Glycerin 100 cc. 



Methylic alcohol 100 cc. 



After two days filter. After several days filter again. The 

 fluid will ripen for several weeks and will require considerable 

 dilution with a saturated aqueous solution of alum, containing 

 glycerin and methylic alcohol in the above proportions. 



This is a very deep nuclear stain, in fact it is so very deep that, 

 while the nuclei are sharply differentiated, the intranuclear struc- 

 ture is nearly obliterated. The stain is somewhat improved in this 

 particular by the slight regressive action of very weak acids e. g., 

 picric, or dilute acetic acid. 

 Mann's Acid Hematein : 



Hematein (Griibler's) 2 grm. 



Absolute alcohol 100 cc. 



Glycerin 100 cc. 



Distilled water 100 cc. 



Potassium alum 10 grm. 



Glacial acetic acid 10 cc. 



The hematein is dissolved in the acetic acid, with 25 cc. of the 

 alcohol ; the glycerin and the remainder of the alcohol are then 

 added. The alum is dissolved in water by the aid of heat, and the 

 warm solution is poured into the solution of hematein. The fluid 

 keeps indefinitely and is an excellent hematein stain for general use. 

 Application of the Hematein Stains. All of the above solutions 

 are used in a similar manner. Sections, either free or attached to 

 the slide, are taken from water and immersed in the dye for three 

 to five minutes ; they are then thoroughly washed in water. The 

 stained sections are at first of a reddish-purple color, but soon 

 become a deep blue from the slight alkalinity of the tap water used 

 for washing. If necessary this alkalinity may be increased by the 

 addition of one or two drops of ammonia to 500 cc. of the water 

 used for washing. 



Methylen Blue. This dye is a derivative of thionin, and may 

 be similarly used. For staining fresh tissues the dye is used in 2 

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