80 GENERAL MICROBIOLOGY 



will have germinated within forty-eight hours after prepar- 

 ing the mount. 



Note. This method may be utilized to study the colony develop- 

 ment of bacteria also. 



EXERCISE 23. PREPARATION OF THE MOIST- 

 CHAMBER CULTURE 



The purpose of the exercise is to study colony formation 

 in molds, yeasts and bacteria. 



Apparatus. Clean cover-glasses; small glass rings, 



FIG. 29. Moist Chamber Culture. (Orig.) 



clean; clean slides; sterile pipette; paraffin or vaselin; 

 sterile distilled water in test tube; tube of a sterile liquid 

 nutrient medium; platinum needle and loop; forceps; 

 cover-glass. 



Culture. Pure culture of organism to be studied. 



Method. 1. With forceps, carefully sterilize in a 

 flame a glass slide and a glass ring designed for this pur- 

 pose. This should be done by a swinging motion to insure 

 uniform distribution of the heat. 



2. Around the edges of the ring, after it has cooled suf- 

 ficiently, place a little vaselin, while the ring is still held 

 in sterile forceps. 



