This is a firm medium that keeps well and makes a good base for egg collecting. Wrap filled petri dishes and store at 4 - 14oC (they should keep for at least 6 weeks). Substitute molasses for the corn syrup if you prefer a dark medium, or add food coloring. This recipe makes about 60 6 x 2 cm plates.
Hard Agar Substrate
|Light corn syrup||350||milliliters|
|10% p-Hydroxy-benzoic acid methyl ester in 95% ethanol||38||milliliters|
Mix water, agar and syrup.
Boil until agar is dissolved.
Cool for 5 minutes or more, stir in p-Hydroxy-benzoic acid methyl ester.
Dispense into petri dishes.
- The amount of agar should be determined empirically for your brand and lot of agar. We buy 100 lb. barrels of "Agar 700" (product #40004) from Mooragar, Inc.
- Corn Syrup
- We use Karo® light corn syrup.