SECTION TWO 



red, by the chromotrope 2R. The non-granular cytoplasm, 

 greyish green or unstained. Coagulated contents of the cyto- 

 plasmic vacuoles, orange. 



Reference: Halmi, Nicholas, S. (1952), Stain Tech., 27, no. i, 61. 



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. 



For bone staining in small vertebrates (Dawson's method) 



Solutions required: 



A. Potass, hydroxide 1% aqueous 



B. Alizarin Red, S o-i gm. 



Potass, hydroxide . . . . 10 gm. 

 Distilled water i litre 



C. MalVs solution: 



Glycerin . . . . . . 20 ml. 



Distilled water . . • • 79 inl- 



Potass, hydroxide . . . . i gm. 



Technique: 



I. Whole specimens are fixed in 95% alcohol for at least three 

 days. 



53 



