MEDIA FOR PROTOZOA 2Q 



To prepare add 30 parts of this alkaline egg mixture to 70 parts of meat extract free 

 3% agar. (No meat extract; only peptone and salt.) The cholera colony has a 

 hazy look, like a little wad of absorbent cotton sticking to the surface with a metallic 

 luster halo. 



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 

 platinum 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; NaCl 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 agg albumin. 

 This may replace water of condensation in an agar slant. 



NOVY 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 normal sodium carbonate solution and 20 to 25 grams agar. Prepare as for 

 nutrient agar and sterilize. To i part of this one-quarter strength meat infusion 

 nutrient agar, when melted and cooled down to 60 C., add twice its volume of de- 



