Media & Biochemical Tests
You will be using a wide variety of media and biochemical tests to isolate
and identify your unknown organisms. Your text has a good section
on enrichment, selective, and differential media. Please
review it before getting started. You are only working with a small
subset of the available media and tests. It is enough however to
give you a good idea of the problem solving that goes on behind
the scenes to support patient care. The information provided on
these pages was derived from the DIFCO Manual of media which is also available in the lab.
The media and test are arranged in alphabetical order. Refer to the information
on each group of organisms to find out which media and tests are
appropriate for that group.
Read the directions carefully. You must pay close attention to the conditions
of the tests and media to avoid erroneous results.
Things to watch for include:
- type of media
you pull your sample from (enrichment or selective)
- mixed or
pure cultures for inoculation
- type of inoculation -
one or more colonies, needle prick from center or whole colony,
light or heavy innoculation
- application -
do you stab, streak or smear the plate or tube
and atmosphere for incubation - some
tests run for longer times if you get a negative result in 24 hours,
others need to run for 4-5 days, others must be read at 24 hours
because the colors change with storage
For technical problems or questions
contact the webmaster.