Iberian fly food

Iberian Drosophila food recipie
(from José Casal)
For 5 litres of food. Put a 5 liter pyrex beaker on a magnetic stirrer heater and boil 3
liters of tap water. Cover with aluminium foil to limit evaporation and speed up the
heating. Remove the foil at the cooling step.
For the following steps, keep the heating plate at 300°C throughout the heating
process. Make sure the magnetic stirrer is on and at high speed througout.
In a food processor, mix together:
500 ml of cold water
220g of D-glucose
200g of dried live yeast (e. g., DCL yeast)
30 g of agar
Add the mix to the boiling water in the large beaker
Separately, in the food processor, mix
140 g of plain wheat flour
600 ml of cold water
Add the mix to the boiling water in the large beaker
Boil for 30 minutes. Switch off heating, top up to 5 liters with cold tap water and wait
until cools down to ~60ºC. Then, add
100 ml Nipagin* (stock solution is 50 g Nipagin powder in 500 ml ethanol +
38 ml of green food dye = 1 bottle, Supercook brand, www.supercook.co.uk)
16 ml proprionic acid
40 ml Penicillin G, Streptomycin sulphate solution** (the same mix that is
used in cell culture. Ours is from Gibco: 10,000 units each antibiotics per ml)
Pour into tubes with a dispenser while it is still warm. Insert cotton plugs when the
food gets hard. To clean the beakers use NaOH pellets or concentrated bleach in a
small amount of warm water.
* also known as Methyl Paraben or Hydroxybenzoic Acid Methyl Ester
** optional, very efficient to get read of bacteria with unhealthy stocks, but obviously
a harsh selecting agent.