Laboratory Outline for General Bacteriology 



16. Don't take all the growth possible for the first inoculation as 

 you will have about nineteen more to make from the same 

 culture. Simply touching the cool sterilized needle to the 

 growth is usually sufficient. 



17. Don't allow the sun to shine on cultures. Sunlight destroys 

 certain species of bacteria very quickly. 



Liquid Media 



18. Don't lay tubes of liquid media on table or hold them so that 

 plugs become wet. Contaminations usually follow wet plugs. 



19. Same as 1 to 13 inclusive for agar slants. 



20. Don't allow air to get into the small inner tube of the fermen- 

 tation tubes. 



21. Don't put loop back a second or third time without steriliza- 

 tion after touching it to litmus paper in testing the reaction. 



22. Don't shake or handle tubes roughly before taking the obser- 

 vations. 



23. Don't make observations or tests of cultures without using 

 uninoculated tubes for controls. 



Plate Cultures 



24. Don't lift covers clear off when adding inoculating material 

 with pipette or loop. 



25. Don't pour agar or gelatin when too hot or too cold. 



26. Don't touch the lip of the tube or flask when removing cotton 

 stopper. 



27. Don't scrape outside of tube or flask on edge of plate when 

 pouring. 



28. Don't leave plates without mixing inoculation with medium. 



29. Don't slop medium onto edges of plates when pouring or 

 mixing. 



30. Don't pour plates in a current of air. 



31. Don't remove or lift cover of plate to see if medium has 

 hardened. 



32. Don't leave plates anywhere except near the center of table 

 to harden as tables are crowning. This makes the layer of 

 medium uneven. 



33. Don't ever carry gelatin plates tipped or invert them to in- 

 cubate. 



34. Don't incubate agar plates right side up as condensation water 

 causes trouble by dropping back from the cover, 



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