2092 Journal of Applied Microscopy 



A Review of the Methods of Staining Blood. 



III. 



B. Acid Stains. 



1. Azoblue. — Griesbach (1886) used Azoblue for staining the blood of fish 

 and tritons. The acidophile granules are stained red. 



2. Congo Red. — Stintzing (1889) stained blood preparations with Congo red 

 which differentiated what he called Congophile granules in certain leucocytes. 

 These were undoubtedly acidophile granules. 



3. Eosin. — This is one of the most important acid stains for the blood. 

 The acidophile granules of the blood were first called eosinophile by Ehrlich 

 because of their affinity for this stain. It enters into the composition of many 

 staining solutions used in the study of the blood, including the neutral eosin- 

 methylen blue staining solutions. Used alone it stains all acidophile elements 

 of the blood eosin red. All of the eosin solutions require well fixed preparations. 



Bizzozero (1884) stained heated preparations of the blood one-quarter 

 hour in a dilute watery solution of eosin. 



Ehrlich recommends a strong solution of eosin in glycerine for staining 

 "eosinophile" granules. Well fixed preparations should be stained at least 15 

 minutes. 



Eosin is often combined with one or more other acid dyes for staining the 

 blood on the supposition that not all acidophile elements are eosinophile. 



4. Eosin, Aurentia, and lodulia. — Ehrlich employed three dyes dissolved in 

 glycerin. With this mixture all hemoglobiniferous parts are stained an intense 

 pure orange, nuclei blackish, acidophile granules red or reddish black. 



Schwarz (1880), who worked under Ehrlich, used the following mixture : 

 1 volume of glycerin saturated with aurentia is mixed with one to two volumes 

 of glycerin. To this mixture is added eosin and aurentia in excess. Saturation 

 follows through long shaking. 



Hiiber and Becker (1880) dissolved two grams of eosin, aurentia, and 

 indulin in thirty grams of glycerin. The mixture should be thoroughly shaken 

 before using. Stain heated preparations one-half hour to several days. 



5. Eosin, Aurentia, and Nigrosin. — V. Norden (1891) gives the following for- 

 mula for an eosin, aurentia, and nigrosin mixture : 



Eosin (cryst.), - 3.0 



Aurentia, ..-.-- 2.0 



Nigrosin (watery solution), - - - 5.0 



These are rubbed together with best, water-free glycerin in a mortar, and at 

 the same time warmed in a sand bath to 80° or 90°C. The viscous mass is 

 then placed in a wide-necked flask, which is stopped with a cork to keep out the 

 steam, and heated for several days in a water bath at 60°C., being thoroughly 

 shaken from time to time. Heated preparations are to be stained 24 to 3(5 

 hours, washed, dried, and mounted. 



6. Eosin and Nigrosin. — Ehrlich and E. Newman used an eosin and nigrosin 

 mixture for the study of nucleated red corpuscles. 



