BACTERIOLOGICAL EXAMINATION OF MATERIAL 213 



blood being sufficent to push up the piston. After the blood has 

 been drawn, it should be immediately transferred to the proper media. 

 Epstein has recently recommended the mixture of the blood with 

 sterile two per cent ammonium oxalate solution in test tubes, by 

 which means the clotting is prevented, and transfers can be made 

 more leisurely to culture media. While this method is convenient 



FIG. 29. BLOOD-CULTURE PLATE SHOWING STREPTOCOCCUS COLONIES. Note halo 

 of hemolysis about each colony. 



in cases where blood must be taken at some distance from the 

 laboratory, it is preferable, whenever possible, to make cultures from 

 the blood immediately at the bedside. 



The choice of culture media for blood cultures should, to a 

 certain extent, be adapted to each individual case. For routine 

 work, it is best to employ glucose "hormone" agar and glucose-meat- 



