-
Sterilize in an autoclave at 121°C for
20 minutes. Cool promptly to 25°C
and store at 20-30°C,
avoiding excess of light. Medium can be used within 3 weeks only.
-
Use Soyabean-casein digest medium by
incubating it at 20-25°C
under aerobic conditions.
Media for Penicillin or Cephalosporins:
Where
sterility test media are to be used in the direct transfer method, modify
the preparation of both the media by transferring aseptically a quantity
of b-lactamase
required to inactivate the antibiotic by using a b-lactamase
preparation that has been assayed previously for its penicillin- or
cephalosporin-inactivating power.
Suitability tests for culture media:
1. Sterility
of media:
Confirm the
sterility of each sterilized batch of medium by incubating a portion of
the batch at the specified incubation temperature for not less than 14
days or by incubating uninoculated containers as negative controls during
sterility test.
2. Growth
promotion test:
Separately
inoculate, in duplicate, containers of each medium with less than 100
viable microorganisms of each of the strains listed below and incubate
according to the conditions specified below. The test media are
satisfactory if visual evidence of growth appears in all inoculated media
containers within 5 days of incubation.
Guidelines for the selection of microorganisms,
their growth conditions for the testing the growth promotion test and test
for bacteriostasis and fungistasis as
per IP.
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