ANTIFORMIN TUBERCLE CULTURES 137 



rial supposed to contain the tubercle bacilli, in a suitable glass 

 container and bring to a boil over the Bunsen burner. When the 

 material is cool, add 1.5 cc. of a mixture of chloroform and alcohol 

 (chloroform one part and alcohol nine parts) to each 10 cc. of the 

 material and shake vigorously. The tubercle bacilli absorb some 

 of the chloroform and become heavier than the rest of the organic 

 matter. Next centrifugalize at a high speed for 15 min. which 

 separates the material into three layers; the antiformin at the top, 

 the sediment in the middle, and the chloroform with the tubercle 

 bacilli at the bottom. Pipette off the layer of chloroform and ex- 

 amine for tubercle bacilli by resorting to the usual staining methods. 

 The smear preparations can be made to stick to the cover or slide 

 by mixing with serum or egg albumen solution. This method may 

 also be tried in the examination of creams, cheese, buttermilk and 

 butter. The strength of the antiformin solution should be graded 

 according to the amount or percentage of organic matter to be dis- 

 solved, taking the strength required for sputum work as the high- 

 est. For milk work the 15 per cent, solution will be satisfactory. 

 For cheese a 50 per cent, solution should be used, likewise for 

 feces. 



Stitt recommends the following antiformin method for cultur- 

 ing the tubercle bacilli. Mix 20 cc. of sputum, 65 cc. of sterile 

 water and 15 cc. of antiformin. Stir with a glass rod. After a 

 period ranging from 30 min. to 2 hr., the mixture should be 

 homogeneous. Centrifugalize for 15 min. or longer, decant, and 

 wash the sediment twice in sterile normal salt solution and smear 

 out the well-washed sediment over serum or glycerin egg albumen 

 or nutrose slants. It must be remembered that the tubercle bacillus 

 will not grow in sunlight and that the colonies form on the surface 

 of the culture media only. 



Stitt also states that it is not wise to use the antiformin in 

 solutions stronger than is necessary to dissolve the organic matter 

 and bacteria other than the tubercle bacillus. For example for 

 sputum, it is suggested that 20 or 25 per cent, of antiformin be 



