172 Medical Bacteriology. 



EXERCISE CV. STAINING SECTIONS. 



GENERAL HISTOLOGICAL METHOD. 

 Hcematoxylin and Eosin. 



a. Transfer sections from alcohol to distilled water. 



b. Stain in aluin-ha8inatox\'lin 2, 5 to 30 minutes. The stain may be prepared as 

 follows (Boehmer): 



1. Haematoxylon crystals, - 1 gram. 

 Absolute alcohol, - - 10 cc. 



2. Alum, - 20 grams. 

 Distilled water, - 200 cc. 



Cover the solutions and allow them to stand over night. The next day mix them 

 and allow the mixture to stand for one week in a wide-mouthed bottle lightly plugged 

 with cotton. Then filter into a bottle provided with a good cork. The solution is now 

 ready for use but its staining powers improve with age. 



c. Wash the sections in several changes of water until they have lost all traces of a 

 red tint. 



d. Counter- stain with eosiu (iV to j % in 60 % alcohol) 1 to 5 minutes. 



e. Alcohol, 95 %, two or three changes to dehydrate and remove excess of counter- 

 stain. 



/. Clear in oil of origanum or Dunham's mixture, white oil of thyme 4 parts, oil 

 of cloves 1 part. 



GENERAL BACTERIOIX)GICAL METHODS. 



A. Loeffler's Universal Method. 



a. Take sections out of alcohol into Loeffler's methvlen blue for 5-30 minutes. 



b. Decolorize iu acetic acid (0. 1%) 10 to 20 seconds. 



c. Dehydrate in absolute alcohol, two or three changes, a few seconds. 



d. Clear in xylene. 

 'e. Mount in balsam- 



B. Weigert's Method. 



a. From alcohol to Ehrlich's anilin water gentian violet 5-15 minutes. 



b. Wash inO. 6% salt solution. 



c. Dry with filter paper. 



d. Place in potassium iodide and iodine solution (iodine 1 part, potassium 

 iodide 2 parts, water 100 parts). 



e. Dry with filter paper. 



/. Decolorize in a mixture of anilin oil 2 parts and xylene 1 part, 2-5 minutes. 



g. Clear in xylene. 



h. Mount in balsam. 



This stain can only be used with those organisms which take the Gram stain, namely: 

 8. pyogenes, M. pyogenes, M. aureiis, Sar. tetmgena, B. anthracis, B. pneumoniae, B. 

 rhusiopathiae, B. tuberculosis, B: leprae, B. diphtheriae, P. aeruginosa, B. Welchii, B. 

 chauvaei. B. oedematis, B. tetani. and Strevtothrix actinomyces. 



