INOCULATION OF GELATIN AND AGAR 63 



Test-tube Cultures. The gelatin, agar, or blood-serum 

 having solidified in an oblique position, is smeared on the surface 

 with the material, and the growth occurs, or the medium is 

 punctured with a stab of the platinum rod containing the 

 material. The former is called a stroke or smear culture, the latter 



Fig. 29. Manner of holding tubes for inoculation: a, Tube with material; 

 b, tube to be inoculated; c, cotton plugs (after Woodhead and Hare). 



a stab or thrust culture. In removing the cotton plugs from 

 the sterile tubes to carry out the inoculation, the plugs should 

 remain between the fingers in such a way that the part which 

 comes in contact with the mouth of the tube will not touch 

 anything (Fig. 30). 



