STAB CULTURES 



n 



surface of the medium in the form of isolated drops, which 

 do not coalesce ; or they may form skin-like ridges, as is 

 the case in the growth of the tubercle bacillus. 



Fig. 17. — Method of making a 'Streak' Culture. 



' Stab ' Cultures. — -A platinum wire inoculated with the 

 infecting material is thrust into the depth of an ordinary 

 culture-tube containing about 10 c.c. of nutrient medium, 

 care being taken to introduce the wire in a central line and 

 in a direction parallel with the sides of the tube. It is 



Fig 18. — Method of making a ' Stab ' Culture. 



best to always hold the tube during the inoculation in an 

 inverted position to prevent the risk of contamination, and 

 to singe the plug before returning it to the tube. 



The characters of the growth in these ' stab ' or ' depth ' 



