SECTION TWO 



Results: 



Mast cell granules: brown. Nuclei: grey (weakly yellowish). 

 Epidermis: slightly yellow. Glands: yellowish. Connective 

 tissue: intense purple. 



In type II cells of abdominal fluids, the granule or its halo of 

 the outer layer is stained weakly with the periodic acid-Schiff 

 procedures. 



Notes: 



(a) The author states that according to Lison (1953) it has 

 been shown that metachromasia of tissue elements is produced by 

 the presence of ribonucleic acid, polysaccharide sulphate ester, 

 metaphosphate, heparin, hyaluronic acid and occasionally deoxy- 

 ribonucleic acid. 



(b) It is also stated in the original paper, to which readers are 

 referred for more detailed information, that the mechanism of 

 chrysoidin staining of the mast cell granules is not due to meta- 

 chromasia but to strong basophilia of mast cell granules, while 

 that of a metachromatic dye consists of two factors: basophilia 

 and metachromasia. 



(c) In his observation of the staining with the combination 

 periodic acid-Schiff-chrysoidin, Harada claims that it is clearly 

 proved that mast cell granules are PAS negative, but intergranular 

 cytoplasm is often slightly PAS negative, and accordingly the 

 PAS reaction is negative in type I mast cells, but a proportion 

 of the granules or their halos in the outer layer of the cytoplasm 

 of type II cells are stained weakly purple. 



(d) In the original paper, solution A is given as: "0-69% 

 potassium periodate in 0-3% nitric acid." This amounts to the 

 same as 0-7% periodic acid, which solution is simpler and quicker 

 to prepare when the solid periodic acid is readily available. 



References : 



Harada, K. (1957). 

 Lison, L. (1953). 



CONGO RED 

 For Amyloid in tissues 



Solutions required: 

 A. Congo Red i% in distilled water. 



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