Laboratory Outline for General Bacteriology 



35. Don't tip agar plates constantly while they are hardening. 

 It breaks the agar so it will not form a solid mass which can 

 be satisfactorily inverted. 



Gelatin Stab 



36. Don't puncture medium with a crooked needle or with the loop. 



37. Don't stop puncturing until the needle touches the bottom of 

 the tube. 



38. Don't split the medium when removing the needle. 



39. Don't puncture near the side of the tube or more than once. 



40. Don't hold the tube in the hand until the warmth of the hand 

 melts the gelatin. 



41. Don't fail to record the form of growth, when liquefaction 

 begins, and when it is complete. 



Morphology 



42. Don't forget to come extra times when necessary to make 

 cultures so as to have them the right age to use at laboratory 

 periods. 



43. Don't use too much or too little material in preparing films. 



44. Don't leave all the material of the film in one small thick 

 mass which can never be seen through. Spread. 



45. Don't leave stains on for longer or shorter times than called 

 for in the directions. 



46. Don't measure less than ten different bacteria before filling 

 in measurements called for. 



47. Don't think the size of a rod simply means its length, or that 

 you multiply the length by the width. 



48. Don't think that most of the information called for under 

 "Morphology" does not amount to much and needs not to be 

 filled out. 



49. Don't make preparations for motility examination until you 

 are ready to examine them, or leave on the full amount of 

 light when trying to find them. 



50. Don't ever touch the surface of a cover glass with the fingers. 

 It leaves enough greasiness to prevent the proper spreading 

 of films. 



27 



