1 88 SPECIAL MEDIA 



Urine Gelatine (Heller). 



1. Collect freshly passed urine in sterile flask. 



2. Filter through animal charcoal to remove part of the 

 colouring matter. 



3. Take the specific gravity, and if above 1010, dilute with 

 sterile water till this gravity is reached. 



4. Add Witte's peptone, i per cent. ; salt, 0.5 per cent.; gelatine, 

 10 per cent. 



5. Heat in the steamer at 100 C. for one hour, to dissolve 

 the gelatine, etc. 



6. Add normal caustic soda solution in successive small 

 quantities, and test the reaction from time to time with litmus 

 paper, until the fluid reacts faintly alkaline. 



7. Cool to 60 C. and clarify with egg as for nutrient gelatine 

 (vide page 166). 



8. Filter through papier Chardin. 



9. Tube, and sterilise as for nutrient gelatine. 



Urine Agar. 



1. Collect freshly passed urine in sterile flask. 



2. Take the specific gravity and if above 1010, dilute with sterile 

 water till this gravity is reached. 



3 . Weigh out i . 5 per cent, or 2 per cent, powdered agar, and add 

 it to the urine. 



4. Heat in the steamer at 100 C. ior ninety minutes to dissolve 

 the agar. 



5. Cool to 60 C. and clarify with egg as for nutrient agar (vide 

 page 1 6 8). 



6. Filter through papier Chardin, using the hot-water funnel. 



7. Tube, and sterilise as for nutrient agar. 

 (Leave the reaction unaltered.) 



Serum Sugar Media (Hiss). 



In these media the fermentation of carbohydrate substance by 

 bacterial action is indicated by the coagulation of the serum 

 proteids in addition to the production of an acid reaction. 



Serum Dextrose Water (Hiss). 



1. Measure out into a litre flask 



Serum water (See page 1 70) 1000 c.c. 



2. Weigh out 



Dextrose 10 grammes 



and dissolve in the serum water. 



3. Filter through Swedish filter paper. 



4. Measure out and add to the medium 



Litmus solution (Kahlbaum) .... 50 c.c. 



