MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



Technique: 



1. Paraffin sections are mounted on the slide and brought down 

 to distilled water in the usual manner. 



2. Stain for six minutes in a freshly prepared mixture consisting 

 of equal volumes of Weigert's haematoxylin A and B. 



3. Wash thoroughly in tap water; then stain for three minutes 

 in the eosin solution. 



4. Wash in tap water ; then immerse in the ferric chloride solu- 

 tion for five minutes. 



5. Rinse well in distilled water; then stain for five minutes in 

 the naphthol green solution. 



6. Differentiate for two or three minutes in 1% acetic acid. 



7. Drain well; then dehydrate with acetone, afterwards clear- 

 ing in acetone-xylol (as above); then mount. 



Results: 



Connective tissue, green; muscle and cytoplasm, pink. 



Reference: Lillie, R. D. (1945), J^. Tech. Meth., 25, 32. 



NEUTRAL RED - FAST GREEN 



For staining both Gram-positive and Gram-negative 



bacteria in sections 



Solutions required: 



A. Aniline crystal violet. 



B. Gram's iodine. 



C. Absolute alcohol . . . . 98 ml. 

 Glacial acetic acid . . . . 2 ml. 



D. Twort's stain, modified (neutral red-fast 



green) 



Technique: 



1. Fix tissue in 5% formal-saline, dehydrate, clear; embed in 

 paraffin wax. Cut sections 3^^ in thickness. 



2. Stain in aniline crystal violet for three to five minutes. 



170 



