SECTION TWO 



3. Pour off excess stain, then blot dry. 



4. Dehydrate in alcohohc iodine (solution B). 



5. Drain, then blot dry. 



6. Clear and differentiate in origanum oil. 

 2. Mount in LPM (see page 523). 



Results: 



Glycogen assumes a mahogany colour, while starch is stained 

 blue. Background: pale yellow. 



Notes: 



The Best's carmine method (page 150) may also be applied: 

 it is considered to be highly specific for glycogen, and while it 

 may stain mucin, fibrin, etc., these are coloured so faintly com- 

 pared with the staining of glycogen that confusion is unlikely. 



References : 



Langerhans (1890). 

 Pearse (1953). 



PERIODIC ACID - SCHIFF - CELESTIN BLUE 



For human and animal pituitary glands, demonstrating 

 both muco-protein precursors of the gonadotrophins 



Solutions required: 



A. Helly Fixative containing 5% of 

 neutralized formalin. 



B. Lugol's iodine. 



C. Sodium thiosulphate 5% aqueous. 



D. Periodic acid as solution A, page 351. 



E. Reducing rinse (Solution C as page 351). 



F. Schiff's reagent 



G. Celestin blue (Lendrum atid Mcfarlane) 



Celestin blue . . . . . . 0-25 gm. 



Iron alum . . . . . . . . 2-5 gm. 



355 



