SECTION TWO 



should be stained in a jar or in a Petri dish, sections face down- 

 wards, to prevent a deposit forming on the sections. 



2. Wash off excess stain with 95% alcohol, and if necessary 

 differentiate in acid alcohol for a few minutes. 



3. Wash quickly with 70% alcohol ; then thoroughly with water. 



4 Counterstain with Van Gieson, Ehrlich haematoxylin or 

 Safranin for about five minutes. 



5. Differentiate, if necessary, in 95% alcohol. 



6. Dehydrate ; clear in xylol and mount. 



Note: If Celloidin or L.V.N, sections are used clear in ori- 

 ganum oil or in terpineol after 95% alcohol. 



Results: 



Elastic fibres, dark blue or black. Nuclei, brilliant red (if Orth's 

 carmine is used) or bluish black (with haematoxylin). Collagen, 

 pink to red ; other tissue elements, yellow (if Van Gieson is used). 



ELASTIN STAIN (Sheridan) 



This stain has an advantage over Weigert's elastin stain in that 

 the solution may be kept for reasonably long periods without 

 deterioration. 



The staining procedure is the same as for Weigert's elastin stain. 



Results: 



Elastic fibres are stained green to greenish black. 



ELASTIN - TRICHROME STAIN 



For the demonstration of elastic, smooth muscle and 

 collagenic fibres with equal clarity, particularly in the walls 



of hlood vessels 



Solutions required: 



A. Weigert's elastin stain 



Weigert's elastin stain powder . . i gm. 



Hydrochloric acid, cone, pure . . 2 ml. 



Absolute alcohol . . . . 100 ml. 



97 



