A DIFFEEENTIAL STAIN for MUSCULAR and FIBEOUS 

 TISSUES. By Charles Powell White, M.D., F.R.C.S., 



Demonstrator of Pathology at the Yorkshire College, Leeds. 



It is often very difficult, especially in morbid histology, to 

 distinguish, under the microscope, between unstriped muscle 

 and fibrous tissue. I wish, therefore, to describe a method of 

 differential staining which in my hands has proved very satis- 

 factory. 



In this method the stains on which I rely are picric acid for 

 the muscle and erythrosine for the fibrous tissue. 



On mixing solutions of these stains, the erythrosine is 

 precipitated since it is insoluble in acid solutions ; but if the 

 mixture is exactly neutralised, the erythrosine re-dissolves, and 

 the result is an orange-coloured solution. This is most 

 easily effected by the addition of calcium carbonate. 



The stain is made up as follows : — 



Saturated solution of erythrosine (Griiber) in 



absolute alcohol . . . , . 4 c.c. 



Saturated solution of picric acid in water , 50 c.c, 



"Water . . . . . . .up to 100 c.c. 



Excess of precipitated calcium carbonate is then added, and 

 the whole is allowed to stand, with occasional shaking, for 15 to 

 30 minutes. 



It is then filtered, and the result is a clear solution containing 

 calcium picrate and erythrosine. 



The method of staining is as follows : — 



1. The sections are stained in htemalum or other nucleus- 

 staining preparation of hajmatoxyline. 



2. After washing, the sections are ' blued ' in a saturated solu- 

 tion of lithium carbonate. 



3. They are then washed thoroughly and placed in the picro- 

 •erythrosine mixture. 



The time durinLf which this stain should act varies somewhat 



