MEDICAL BACTERIOLOGY 



filling the tubes with a jacketed test-tube filler constructed to guard the upper 

 part of the tube from contact with media. 



After media has been run into tubes, they are never tilted, slanted or shaken 

 to a degree that would send the media into contact with the plugs. 



When using tubes 5 or 6 inches long they are usually filled to a depth of 



FIG. 7. 



SMEAR-CULTURE. This tube shows the 

 rubber cap used to prevent drying. 



STAB-CULTURE. A rubber stopper may be 

 used to prevent drying. 



about 2 inches with liquid media, such as bouillon, about the same with solid 

 media intended for plating and stab cultures. 



To obtain surface growth on solid media in test-tubes, immediately] after 

 sterilization, while the media is still liquid, the tubes are slanted and permitted 



FIG. 8. PETRI DISH (MacNeal). 



to remain so until the media solidifies; these tubes should contain such a quantity 

 of media and be slanted at sucK an angle that when solid the media will entirely 

 fill the bottom % inch of the tube, the upper portion being at least an inch below 

 the plug. 



Covered glass dishes Petri dishes are frequently employed when a broad 

 surface growth on solid media is desired. They are shallow and intended to 



