MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



(IV) Beta cells of the pancreatic islets of all species, after 

 formalin, mercuric chloride-formalin or Bouin. Particular beauti- 

 ful results are obtained in the islets of man and the sheep (the beta 

 cells of the latter are particularly difficult to stain otherwise). 



(V) Functioning tumours of the islets are also stained select- 

 ively. 



(VI) Certain basophils of the anterior pituitary, after the same 

 fixatives as in (V). In the pituitary of the rat and of the pig the 

 two kinds of basophils are usually quite conspicuous. 



Notes: 



{a) After fixatives containing mercury the background is pale 

 mauve. After formalin or Bouin the background is colourless. 



ifi) If the stain is prepared by adding paraldehyde to Feulgen's 

 fuchsin the resultant solution will stain the beta cells very distinctly 

 but leave the elastic fibres unstained. Old solutions of the aldehyde 

 fuchsin will stain elastic fibres very selectively, but leave the beta 

 cells unstained. 



Reference: Gomori, G. (1950), Am. J. Clin. Path.y 20, No. 7, 665-6. 



ALDEHYDE FUCHSIN - HAEMATOXYLIN LIGHT GREEN - 

 ORANGE G . CHROMOTROPE 



For the diflFerentiation of two types of Basophils in the 

 Adenohypophysis of the rat and the mouse 



Solutions required: 

 A. Benin's fixative with the acetic acid replaced 



50 



