STAINING, PRACTICAL AND THEORETICAL 



can be applied for the chromophobes, in the authors' hands 

 luxol fast blue appeared to be the most satisfactory. 



(b) The authors also state that as permanganate oxidation 

 appears to be essential for staining with aldehyde thionin and 

 permanganate will not materially alter the sulphate groups of 

 polysaccharides, it is possible that some other mechanism must 

 be involved to account for the specific staining encountered. 



Permanganate oxidation, although freeing glycol groups, is said 

 to destroy them. As the authors point out, it must be supposed 

 that the oxidation does not proceed to the point at which destruc- 

 tion of the groups so freed makes any appreciable difference to 

 the colour formed, since the colour of leuco fuchsin is restored 

 presumably by such groups (i :2-glycol). 



(c) Readers are referred to the original paper, which carries 

 two photomicrographs, for more detailed information. 



Reference: Paget, G. E. & Eccleston, Enid (i960). 



ALIZARIN RED, S 

 For calcium deposits in cartilagenous and embryonic bone 



Solutions required: 



A. Alizarin Red, S, aqueous 1% 



B. Polychrome Methylene Blue (Unna) 



Technique: 



Tissues are fixed in 80-90% alcohol and embedded in paraffin 

 wax. 



1. Sections are brought down to distilled water; then stained in 

 Solution A for five to sixty minutes, according to the material. 



2. Wash with distilled water, followed by 95% alcohol at 60° C. 



3. Counterstain with Solution B for one to three minutes. 



Results: 



Cartilage: intense violet. Calcium: red. Nuclei: blue. Cyto- 

 plasm, etc.: yellow. 



The method is particularly suitable for pathological specimens. 



124 



