SECTION TWO 



B. Acetone . . . . . . . . loo ml. 



Orange G aqueous 2% . . . . About lo ml. 



Add orange G solution drop by drop to the ace- 

 tone, with shaking, until the flocculent precipitate 

 formed just redissolves with further addition of 

 orange G solution. 



Technique: 



1. Small pieces of tissue are fixed in acetic-alcohol or in mer- . 

 curie chloride. 



2. Wash; dehydrate; clear; embed in paraffin wax. 



3. If mercuric chloride has been used for fixation treat sections 

 for the removal of mercuric precipitate by the standard method. 



4. Take sections down to distilled water. 



5. Immerse for two minutes in the methyl violet pyronin 

 (Solution A above). 



6. Pour off excess stain and carefully wipe the slide dry. 



7. Flood the preparation with acetone-orange G solution. 



8. Pour off after a few seconds. 



9. Flood the preparation with a fresh lot of acetone-orange G 

 solution and pour off after a few seconds. 



10. Wash quickly in pure acetone. 



1 1 . Rinse with two lots of xylol. 



12. Mount in balsam. 



Results: 



Cytoplasm, red; chromatin, violet; keratin, violet; connective 

 tissue, yellow. 



METHYLENE BLUE - BASIC FUCHSIN 

 Rapid method of demonstrating. Negri bodies in sections 



