Making Media and Pouring
- Fresh green string beans. Purchased at any grocery store. You will
need about 1/8th of a pound.
- Agar (use soup agar 10 grams per 2 bars) This can be purchases in any
Philippine or Japanese grocery store.
- One cup of tap water (heated to boiling)
- Glass or microwave safe containers to hold media
- Petri plates. Any size will work; however, the easiest to work with
are the smaller ones. (50mm X 9mm).
- Small pot
- Into blender add 1 cup boiling water and green beans. Turn blender on
to highest setting and let run for 5 - l0 minutes. The goal is to liquefy all of the
- Pour the mixture through the strainer. This will remove any of the
large pieces of bean.
- Add more water to make solution 1 cup again.
- Place mixture in a pot on stove top and bring to a light boil.
- Add approximately ¾ of a bar of agar (approximately 4 grams) and
continue to boil until agar dissolves.
- Pour the solution into a microwave safe containers, cover and place
in microwave. Also place 1 - 2 liters of water in a separate container in the microwave to
prevent the solution from boiling over.
- Bring the media to a boil in microwave. As soon as the media begins
to boil turn off the microwave. Let the media cool for 4 hours.
- Repeat the boiling process after the 4 hours of cooling.
- Allow media to cool until mixture is warm to touch, however, not
solidified. Add 0.5 cc of Gentamicin Sulfate per 10 cc of solution (1.5 cc per cup)
- After Gentamicin is added and mixed (mixing is accomplished by
swirling solution in containers), pour the media into the culture plates. Lift the lid of
the culture plate only as much as necessary to all for pouring of solution. Immediately
replace lid. Only fill bottom portion of culture plate 2/3 of the way.
- Stack the culture plates as you go (i.e. place the next plate to be
poured on top of the one just finished) This prevents condensation from the warm media to
collect on the lid and obscuring the view of the plate.
DO NOT MOVE THE PLATES FOR SEVERAL HOURS, UNTIL THE MEDIA HAS
REMEMBER TO POUR THE MEDIA IN A LOW TRAFFIC AREA TO PREVENT
ACCIDENTAL BUMPING OF THE PLATES.
- Excess media may be discarded, or stored in the refrigerator in
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