Laboratory Outline for General Bacteriology 



5. Pour three plates with agar. When cool sneeze into one, 

 cough into another and place a hair in the third. 



6. Catch two flies and place them in bottle with 100 cc. of 

 sterile water. Shake 5 minutes and plate using 



1 cc. .5 cc. .2 cc. .1 cc. 



7. Shake a dishcloth, which has been used twice in ordinary 

 way since being thoroughly boiled, in 1000 cc. of sterile water. 

 Plate using 



1 cc. .5 cc. .2 cc. .1 cc. 

 Pour agar in plates and incubate 2 days at 37 C. and study. 



8. Flame a clean glass slide, cool, and touch lip to it as much 

 as you would touch it to a glass in drinking, Dry, and pass three 

 times through flame. Stain 1 minute with watery fuchsin. Wash, 

 dry and examine under the microscope using the oil immersion 

 objective. Note the forms and arrangement of the bacteria pres- 

 ent and the approximate number of bacteria per field. 



9. Sterilize platinum loop, cool, scrape along the teeth near 

 the gums. Mix with drop of water on a slide. Spread, dry, flame 

 three times, stain 1 minute with watery fuchsin, wash, dry, and 

 examine under the miscroscope using the oil immersion objective. 

 Note the forms, arrangement, and abundance of the bacteria. 



DISTILLED WATER EXPERIMENT 



To demonstrate the small amount of food needed by bacteria, 

 and that distilled water is not the same as sterile water. 



Draw off 100 cc. of distilled water into each of two sterile 

 flasks. Mark them "A" and "B". 



Sterilize flask "A" in autoclav for 15 minutes at 10 pounds 

 pressure. When cool make an agar plate from each flask using 

 1 cc. for inoculation. 



Inoculate flask A with a very small amount of B coli. Shake 

 and plate 1 cc. in agar. 



Keep flasks and plates in locker. 



After five days count plates and make others from flasks 

 using dilutions of 1-10, 1-100, and 1-1000. 



After 5 days count and find whether there has been an in- 

 crease or decrease in the numbers of bacteria. 



