SERUM AGAR 211 



2. Make reaction of medium + 10. 



3. Filter; tube in quantities of 6 c.c. 



4. Sterilise as for nutrient agar. 



5. After the third sterilisation cool the tubes to 42 C., and 

 add to each 3 c.c. of sterile hydrocele fluid, ascitic fluid, or pleuritic 

 effusion (previously sterilised, if necessary, by the fractional 

 method) ; allow the tubes to solidify in a sloping position. 



6. When solid, incubate at 37 C. for forty-eight hours, and 

 eliminate any 'contaminated tubes. Store the remainder for 

 future use. 



Serum Agar (Wertheimer) . 



1. Prepare nutrient agar (vide page 167), to the following 

 formula : 



Agar 2.0 per cent. 



Peptone 2.0 per cent. 



Salt 0.5 per cent. 



Meat extract quantum sufficit. 



2. Make reaction of medium + 10. 



3. Filter; tube in quantities of 5 c.c. 



4. Sterilise as for nutrient agar. 



5. After the last sterilisation cool to 42 C., then add 5 c.c. 

 sterile blood-serum from human placenta (sterilised, if necessary, 

 by the fractional method) to each tube; slope the tubes. 



6. When solid, incubate at 37 C. for forty-eight hours, and 

 eliminate any contaminated tubes. Store the remainder for 

 future use. 



Serum Agar (Kanthack and Stevens). 



1. Collect ascitic, pleuritic, or hydrocele fluid in sterile flasks 

 and allow to stand in the ice-chest for twelve hours to sediment. 



2. Decant 1000 c.c. of the clear fluid into a measuring cylinder 

 and transfer to sterile litre flask. 



3. Add 0.5 c.c. dekanormal NaOH solution for every 100 c.c. 

 serum (i.e., 5.0 c.c.), and mix thoroughly. 



4. Heat in the steamer for twenty minutes. 



5. Weigh out 15 grammes agar, emulsify in a separate vessel 

 with 200 c.c. of the alkaline fluid previously cooled to about 

 20 C., and then add to the remainder of the fluid in the flask. 



6. Bubble live steam through the mixture for twenty minutes 

 to dissolve the agar. 



7. Filter through papier Chardin, using a hot-water funnel. 



8. Weigh out glucose 10 grammes ( = i per cent.), and dissolve 

 it in the clear agar. 



8a. If desired, add glycerine, 5 per cent., to the clear agar. 



9. Tube, and sterilise as for nutrient agar. 



