Dilution bottles shall be filled with the proper amount of tap water so
that after sterilization they shall contain exactly 9 cc. or 99 cc. as
desired. The exact amount of water can only be determined by experiment
with the particular autoclav in use. If desired, the 9 cc. dilution may
be measured out from a flask of sterile water with a sterile pipette.
Dilution bottles shall be sterilized in the autoclav at 15 lbs. (120°
C.) for 15 minutes after the pressure reaches 15 lbs.
The sample bottle shall be shaken vigorously 25 times and 1 cc.
withdrawn and added to the proper dilution bottles as required. Each
dilution bottle after the addition of the 1 cc. of the sample, shall be
shaken vigorously 25 times before a second dilution is made from it or
before a sample is removed for plating.