1652 Journal of Applied Microscopy 



ELEMENTARY MEDICAL MICRO-TECHNIQUE. 



For Physicians and Others Interested in the Microscope. 



Copyrighted. 

 II. 



BACILLUS TUBERCULOSIS. 



The sputum should be collected in the morning, and great care should be 

 taken to obtain a representative sample and to prevent infection from careless 

 handling. The patient should be instructed to expectorate in a bottle or tin box, 

 and to be sure that the sputum comes from the lungs and not merely from the 

 throat or nose. To prevent contagion collect the sputum in a wide mouthed one- 

 ounce morphine bottle, in which put a small shell vial with a little cotton in it, 

 dropping thereon two or three drops of formaldehyde. The vial should be long 

 enough that it will not lie flat in the morphine bottle, yet not so long but that a 

 well fitted cork could be put in place above it. The vapor from the formalde- 

 hyde will sterilize the sputum, but will not impair its staining properties. Spre.id 

 a thin film of the sputum, selecting a cheesy particle, on a cover-glass held with 

 the Cornet forceps, using the inoculator for this purpose, which should be steril- 

 ized before and after using. Allow the film to dry in the air, after which pass it 

 rapidly three times through an alcohol or Bunsen flame. Stain with carbol fuch- 

 sin, which may be purchased ready for use or be made after the following formula : 



Fuchsin (basic) - - 1 gram. 



Absolute alcohol - - 10 c. c. 



Carbolic acid, five per cent., in distilled water - - 100 c. c. 



Put on the cover-glass with a pipette all of the stain that will readily remain. 

 Hold the cover over an alcohol or Bunsen flame and heat carefully until the 

 stain steams. Allow the heated stain to act for three minutes, drain off surplus, 

 but without washing proceed to decolorize and counterstain at the same time 

 by using the following methylen blue solution, known as Gabbett's blue, which 

 may be bought ready for use or prepared as follows : 



Methylen blue, powder ...--- 2 grams. 

 Sulphuric acid, ten per cent., in distilled water - - 100 c. c. 



Apply this stain to the cover-glass and allow it to act one minute, then rinse 

 in water. If the film has a decided bluish tint it is ready for examination ; if not, 

 the blue stain should be again applied and allowed to act a little longer, after 

 which the cover should be again rinsed in water, then in alcohol, dried, and 

 mounted in a drop of balsam on a clean slip. The tubercle bacilli being exceed- 

 ingly difficult to stain are in this way stained a deep red with the heated carbol 

 fuchsin. As they are very difficult to decolorize, they retain their red color in 

 the presence of the acid of the methylen blue solution, which decolorizes and 

 stains blue all other bacteria. In preparations stained by this method the tuber- 

 cle bacilli will appear as slender, more or less curved rods of a deep reddish 

 color. All other bacteria and tissues will appear of a deep blue color. The 

 diagnosis may readily be made by these peculiarities in the staining of the 

 organism. 



