742 HISTOLOGIC TECHNIC 



The ingredients should be mixed as above and allowed to stand for 

 eight to ten days in an open bottle and exposed to sunlight. Filter. 

 Eipening will continue for some weeks, and the dye will require dilution 

 from time to time with a saturated solution of potassium alum. 



Delafield's Hematoxylin : 



Hematoxylin 4 grm. 



95 per cent, alcohol 25 c.c. 



Saturated aqueous solution of ammonium alum 400 c.c. 



Mix as above and permit the fluid to stand in an open vessel ex- 

 posed to the air and sunlight for three or four days. Add: 



Glycerin 100 c.c. 



Methylic alcohol 100 c.c. 



Expose to light in a cotton-plugged bottle. After two days filter. 

 After several days filter again, and keep in tightly stoppered bottle. 

 The fluid will ripen for several weeks and may require 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 deep that, while 

 the nuclei are sharply differentiated, the intranuclear structure is nearly 

 obliterated. The stain is somewhat improved in this particular by the 

 slight regressive action of very weak acids e.g., hydrochloric, picric, or 

 dilute acetic acid. This is a very useful dye for the toto staining of 

 small embryos. 



Mann's Acid Hematein (Ehrlich's Hematoxylin) : 



Hematein (Griibler's) or hematoxylin crystals 2 grm. 



Absolute alcohol 100 c.c. 



Glycerin 100 c.c. 



Distilled water 100 c.c. 



Potassium alum 10 grm. 



Glacial acetic acid 10 c.c. 



The hematein (or hematoxylin) is dissolved in the acetic acid, with 

 25 c.c. 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 slowly while stirring into the solution 

 of hematein. The fluid keeps indefinitely and is an excellent hematein 

 stain for general use. Hematoxylin solutions may be ripened immedi- 

 ately by the addition of small amounts of hydrogen peroxide (about 1 

 c.c. to 200 c.c. of stain, neutralized by a few grains of sodium chlorid). 



