STAINING REAGENTS, 8 1 



cells of the villi are blue, the goblet cells reddish ; in a hair-follicle 

 the sheath of Henle is an intense red, and the sheath of Huxley 

 blue. 



5. Ehrlich-Biondi-Heidenhain Stain. 



Saturated watery solution of orange . 100 cc. 



,, ,, ,, acid fuchsia . 20 ,, 



,, ,, methyl-green . 50 



To get complete saturation it is necessary to have an excess of 

 the crystals for several days. Each fluid is saturated separately. 

 Before use, the solution is diluted in the proportion of i in 100 with 

 water, and then on the addition of acetic acid must be bright red. 

 It is better to obtain the mixture from Dr Griibler. 

 Application. 



(1.) Harden the organ in corrosive sublimate. 



(2.) Stain sections in the dilute solution (12-24 hours). 



(3.) Wash quickly in 90 per cent, alcohol. 



(4.) Dehydrate in absolute alcohol. 



(5.) Xylol-balsam. 



It is especially useful for sections containing many leucocytes, 

 and is best used for paraffin sections fixed on a slide. Red blood- 

 corpuscles are stained red, resting nuclei blue, mitotic figures and 

 nuclei of leucocytes green-violet. 



General Remarks on Staining. Filter the staining fluid. 

 When possible, use a weak solution of the dye, and thus let the 

 sections stain slowly in a fairly large amount of the fluid. Place a 

 piece of blotting-paper on the inside of a large watch-glass, pour 

 some of the diluted stain into the watch-glass, and place the sections 

 in it. The sections should lie as flat as possible, and not overlap 

 each other. The sections may be moved gently in the fluid by 

 means of a needle. Cover the watch-glass with another glass of 

 the same size, or set it aside in a moist chamber, e.g., on a plate 

 covered by a bell-jar, with a piece of moistened blotting-paper 

 attached to the inside of the jar (fig. 47). After staining, the 

 sections are to be carefully washed in distilled water to remove any 

 trace of surplus dye (except in the case of picro-earrnine). Sections 

 stained with hsematoxylin should be washed for a long time in 

 water before they are mounted in glycerine or Farrant's solution. 



Be careful not to over-stain the tissue, except in those cases 

 where the excess can be again removed, e.g., with the aniline 

 dyes by means of alcohol or acid alcohol. 



All acids should be removed from the sections before they are 

 placed in the dye. 



It is convenient on many occasions that the student should 

 rapidly stain his sections on a slide, but he should also be taught 

 y F 



