76 ESSENTIALS OF BACTERIOLOGY 



(A) Conradi-Drigalski Medium 



Fresh meat 1500 gm. 



Water 2000 c.c. 



Mix and allow to stand twelve hours. Strain, boil one 

 hour, and add 



Peptone 20 gm. 



Nutrose 20 " 



NaCl 10 " 



Boil one hour, filter, then add 

 Agar 60 gm. 



Boil one hour in autoclave or until agar is dissolved. 

 Render weakly alkaline to litmus, filter, and boil one-half 

 hour. 



(B) 



Litmus solution (Kahlbaum) 300 c.c. 



Lactose 30 gm. 



Boil fifteen minutes. Mix with solution A, and make 

 slightly alkaline with soda solution. Then add 4 c.c. 10 per 

 cent, soda carbonate solution (hot sterile) and 20 c.c. of 

 sterile i : 1000 crystal violet solution (Hochst B). 



Lactose-bile (Jackson). Sterilized undiluted ox-gall, 

 98 parts; or dry bile, 10 per cent, solution; peptone, i part; 

 lactose, i part. M. Filled into fermentation tubes, 40 c.c. 

 each, sterilized fractional method. 



Blood-agar. Human or other blood is obtained direct 

 from the body under strict aseptic conditions, and a few 

 drops smeared over the surface of agar in tubes or plates. 

 These are then placed in the incubator for a few days, and the 

 contaminated ones are rejected. This medium is used for 

 influenza bacilli and gonococci. 



Eisner's Medium (for Typhoid) (Potassium lodid 

 Potato-gelatin). Five hundred grams of peeled and 

 washed potatoes are mashed and pressed through a fine 

 cloth. The juice is allowed to settle, is filtered, and after 

 one hour's cooking has added to it 10 per cent, gelatin; then 



