CULTUKE MEDIA 63 



shaking with glass beads or with a coil of fine wire, and 

 the defibrinated blood, warmed to 45 C. ? is added to 

 sterile agar liquefied by boiling and cooled to 45 C. 

 Haemoglobin agar may be prepared by laking defibrinated 

 blood by the addition of sterile distilled water and adding 

 to the liquid agar as before. Blood agar cannot be 

 sterilised after preparation, and the blood therefore must 

 be sterile. 



Alkali albumen (Lorrain-Smith). To 100 c.c. of fresh 

 serum add 1 to 1*5 c.c. of a 10 per cent, caustic soda 

 solution ; mix and introduce into test-tubes in the ordinary 

 way. Place the test-tubes in the slanting position in the 

 autoclave at 115 C. for twenty minutes, or in the steamer 

 on three successive days. 



Egg cutiures (Hueppe). These are very useful for some 

 purposes. A hen's egg is taken and one end sterilised by 

 washing with carbonate of soda solution, rinsing in sterile 

 water, soaking in 1-500 corrosive sublimate solution, and 

 washing in alcohol and in ether. A small hole is then 

 chipped in the shell with a sterile needle and the inocula- 

 tion made through this. The hole is afterwards closed 

 with a little sterilised wool and collodion. 



Uschinsky's Fluid. Parts. Pasteur's Fluid. Parts. 



Sodium chloride . . 5-7 Cane sugar ... 10 



Calcium chloride . . 0-1 Tartrate of ammonia . 1 



Magnesium sulphate . 0-2-0-4 The ash of 1 grm. of 



Di-potassium phosphate 2-2-5 yeast ... 



Ammonium lactate . 6-7 Water .... 100 



Sodium asparaginate . 3-4 



Glycerin . . . 30-40 



Water .... 1000 



Uschinsky's fluid is a solution of known composition without 

 protein which can be used for investigating the chemical product 

 of bacteria. Pathogenic organisms grow well in it and produce 

 their toxins. 



Pasteur's fluid is a good culture medium for yeasts, etc. 1 



1 Several formulae for synthesised media will be found in the Journal 

 of Experimental Medicine, vol. iii, p. 666. 



