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d. Touch the needle to the medium in the culture tube
to be sure it is cooled, and then to the culture mass.
Apply the needle to the sterile medium in the other
tube (Figure 10). (This may be done either by streak-
ing the surface of a slant, making a stab into a semi-
solid media, or swirling the needle in a broth.) If Petri
plates are used, place them on the table and lift the
cover only enough to maneuver the needle when in-
oculating. It should be noted that it is not necessary to
attempt to remove a large volume of the culture mass
with the needle. A slight touch will place more than
enough on the needle to make the inoculation.
Figure 9
e. Flame the mouths of the tubes and cap them.
f. Flame the inoculating needle until it is "red hot".
Figure 10
8. If screw cap culture tubes are used, the cap should be kept loose to allow the aerobic cultures to
get oxygen. (Most common bacteria and molds fall into this category.)
9. If cultures are to be kept for an extended period, however, they should be sealed tightly to prevent
dehydration of the media. Then refrigerate to slow the metabolic processes of the organisms,
unless the label states no refrigeration.
