STAINING, PRACTICAL AND THEORETICAL 



Notes: 



(a) The authors used adjacent sections from the same human 

 pituitary tissue block and stained them by (i) the periodic acid- 

 Schiff method, (ii) Masson trichrome method, and (iii) the luxol 

 fast blue method described above to prove, by comparison of the 

 sections stained by these different techniques, that Luxol fast 

 blue stains the alpha cells an intense blue but does not stain the 

 beta cells. 



{b) Whereas beta cells stained by PAS or by Masson trichrome 

 methods exhibited fine granules, granules were not seen in Luxol 

 fast blue-stained alpha cells. 



(c) The authors state that their findings throw no further 

 light on the suggestion of Kliiver (1944) that the staining reaction 

 of Luxol fast blue is due to porphyrin, or to that of Pearse (1955) 

 that it is due to phospholipids. 



(d) The authors also state that their studies demonstrate that 

 Luxol fast blue is highly selective for alpha cells in the human 

 and a series of other mammahan pituitaries (cat, cow, dog, horse, 

 jackal, pig, rabbit, and rat), and that their conclusion is diametric- 

 ally opposed to that of German & Schwarz (1958). 



(e) For more detailed information and photomicrographs, the 

 original paper should be consulted. 



Reference: Shanklin, William M., Nassar, Tamir K., Issidorides, Marrietta 

 (1959). 



B. 



272 



