EGG MEDIA 45 



then be sterilised in the steam steriliser. Of this solution three 

 parts are added to seven parts of ordinary peptone-agar rendered 

 neutral to litmus, and the mixture is disposed in test-tubes. 



Novy and MacNeal's Medium for Culture of Trypanosomes. 125 



grammes rabbit or ox flesh are treated with 1000 c.c. distilled water, 

 as in making ordinary bouillon, and there are added to the meat 

 extract 20 grms. Witte's peptone, 5 grms. sodium chloride, 20 grms. 

 agar, and 10 c.c. normal sodium carbonate. The medium is placed in 

 tubes and sterilised in the autoclave at 110 C. for thirty minutes. It is 

 cooled at 50 C., and there is added to the medium in each tube twice 

 its volume of defibrinated rabbit blood, which has been prepared with 

 all aseptic precautions ; the tubes are allowed to set in the inclined 

 position. In inoculating such tubes they are placed in an upright 

 position for a few minutes, and then the infective material is introduced. 



EGG MEDIA. 



Within recent years media containing either the yolk or both 

 the yolk and the white of egg, have been used for the culture 

 of the tubercle bacillus by Dorset and others. The following 

 will be found very suitable. 



Dorset's Egg Medium. The contents of four fresh eggs are 

 well beaten up, 25 c.c. of water are added and thoroughly 

 mixed, the mixture being passed through muslin to remove 

 air bells. The fluid is then filled into tubes, and these 

 are heated for four hours in the sloped position at 70 C. 

 Before the inoculation of a tube, two drops of sterilised water 

 are placed on the surface. The inoculation material is well 

 rubbed over the surface of the medium, the tubes are 'sealed with 

 a few drops of paraffin on the top of the plug and are incubated 

 in the sloped position. A better method to solidify the medium 

 is to place the tubes high up in a Koch's steriliser for 

 3-5 minutes. The medium may be further sterilised by placing 

 the tubes in the autoclave at 105 C. for 5-10 minutes, 

 all the valves being tightly screwed up before heating is 

 commenced ; by this means splitting of the medium is prevented. 

 The addition of a sufficient quantity of a solution of basic 

 fuchsin to colour the medium a pale pink is of advantage, as it 

 makes the early growths more easily seen (Cruickshank). 



Glycerin Egg Medium (Lubenau). 200 c.c. of 5 per cent, 

 glycerin bouillon, 1*5 per cent, acid to phenol-phthalein, are 

 added to ten fresh eggs beaten up, and are thoroughly mixed. 

 The medium is then treated as above. An equally good medium 

 may be prepared by adding one part of 6 per cent, glycerin, 

 in '8 per cent, sodium chloride solution, to three parts of 

 beaten egg. 



