124 DEMONSTRATING BACTERIA IN TISSUES 



METHOD. 



1. Prepare the sections for staining, secundum artem. 



2. Stain sections in the warm (e. g., in the hot incubator) for 

 twenty-four hours. 



3. Wash with water. 



4. Decolourise lightly with acetic acid, i per cent. 



5. Dehydrate rapidly with absolute alcohol. 



6. Clear with xylol. 



7. Mount in xylol balsam. 



To Demonstrate Acid=fast Bacilli. 



1. Prepare the sections for staining in the usual way. 



2. Stain with haematin solution ten to twenty sec- 

 onds, to obtain a pure nuclear stain ; then wash in water. 



3. Stain with carbolic fuchsin twenty to thirty 

 minutes at 47 C. ; then wash in water. 



4. Treat with aniline hydrochlorate, 2 per cent, 

 aqueous solution, for two to five seconds. 



5. Decolourise in 75 per cent, alcohol ^till section 

 appears free from stain fifteen to thirty minutes. 



6. Dehydrate with absolute alcohol. 



7. Clear very rapidly with xylol. 



8. Mount in xylol balsam. 



To Demonstrate Spirochsetes in Tissues. 

 Piridin Method (Levaditi). 



1. Cut slices of tissue i mm. thick. 



2. Fix in 10 per cent, formalin solution for twenty- 

 four hours. 



3. Wash in water for one hour. 



4. Place in 96 per cent, alcohol for twenty-four hours. 



5. Measure into a dark green or amber bottle 100 c.c. 

 silver nitrate solution i per cent., and 10 grammes pyri- 

 din puriss. Transfer slices of tissue to this. Stopper 

 and keep at room temperature three hours, then in 

 thermostat at 50 C. for four to six hours. 



6. Wash quickly in 10 per cent, pyridin solution. 



7. Reduce silver by transferring slices of tissue to 

 following solution for forty-eight hours. 



