N. N. N. MEDIUM 35 



RUSSELL'S DOUBLE SUGAR AGAR 



A fairly stiff agar (2 to 3%) with a reaction of about plus 0.7 is colored with litmus 

 solution to produce a distinct purple- violet color. It may be necessary to add more 

 alkali. To this litmus tinted agar is added i% of lactose and 0.1% of glucose and 

 the medium as thus prepared is tubed and slanted. Sterilization should be carried 

 on in the Arnold, on two successive days, as the autoclave temperatures tend to 

 break up the sugars. 



On these slants typhoid shows a delicate growth on the violet slant with a deep 

 pink in the butt of the tube. The paratyphoids show gas bubbles in a pink butt with 

 a violet slant. 



The colon bacillus turns both slant and butt a deep pink and the butt is filled 

 with gas bubbles. To inoculate this medium we take material from a suspicious 

 colony grown on Endo and smear the material on the slant; then with the same plati- 

 num needle we stab into the butt. 



Culture Media for Protozoa 



MEDIUM OF MUSGRAVE AND CLEGG 



Dissolve in 1000 c.c. of water 0.3 to 0.5 gram Liebig's extract and 0.3 to 0.5 

 gram of common salt. If desired for plating add 2 to 3% of agar. 

 A very satisfactory substitute is ordinary nutrient bouillon diluted one to ten. 



MEDIUM OF SMITH 



Glucose i.o gram; Peptone i.o gram; Nad 0.2; Aqua destill. 1000.0; Na 2 CO 3 0.3. 

 Agar q. s. is added for solid medium. 



MEDIUM OF CASTELLANI 



This is an aqueous medium containing i% of lactose and 10% of egg albumin. 

 This may replace water of condensation in an agar slant. 



AUTOLYZED TISSUE MEDIA 



Couret and Walker have possibly grown amoebae from liver abscess on autolyzed 

 tissue media. Sterile organs from healthy animals as well as human placenta are 

 placed in sterile flasks and kept in a thermostat at 4oC. for about two weeks. The 

 liquid from the autolyzed tissues should be about neutral and is either applied to 

 the surface of agar slants or is mixed with melted agar. The medium is then 

 sterilized. 



Now MACNEAL MEDIUM 



Cover 125 grams of chopped up beef with 1000 c.c. of water and place over night 

 in the refrigerator. Strain and add 20 grams of peptone, 5 grams salt, 10 c.c. of 



