Fly Food Preparation

DROSOPHILA MEDIUM PREPARATION

This protocol is based on the Nutri-Fly recommended preparation protocol (Genesee Scientific) and Bloomington Fly Food Prep method (Bloomington Drosophila Stock Center)

Materials Used

· Nutri-Fly Bloomington Formulation 1L packets - Genesee Scientific Cat# 66-112

· Propionic Acid (Certified 99%) - Fisher Scientific Cat# A258-500

· Wide Polystyrene Vials - Genesee Scientific Cat# 32-110

· Flugs® Vial Closures - Genesee Scientific Cat# 49-101

· Cardboard Trays and Dividers - Genesee Scientific Cat# 32-125/32-127

· Cheesecloth - Genesee Scientific Cat# 53-100

· Glad Press’n Seal® - Genesee Scientific Cat# 88-142

· 2 L Pyrex Beaker

· Large Wooden Spoon

· Hotplate

Protocol

1. Empty entire contents of Nutri-Fly packet into a 2L Pyrex Beaker

2. Add 500 ml of room temperature dH₂O and stir out any clumps

3. Add remaining 500 ml of dH₂O and stir

4. Bring to a boil, then immediately reduce heat and cover

5. Simmer for 10 minutes, stirring occasionally

6. Remove from heat

7. Add 4.8 ml propionic acid (Final concentration 0.5%) and stir

Caution: Propionic acid is flammable and can cause burns by all exposure routes. Do not use near heat, sparks, or flame. Safety goggles, lab coat and gloves MUST be worn when handling propionic acid.

8. Allow to medium cool to ~70°C and pour or ladle into vials or bottles according to the table below:

Note: Vials should be placed in divided cardboard trays before pouring fly medium

9. Cover filled vials with a layer of cheesecloth at room temperature until cooled (~2 hours)

10. Cover each tray of medium with a sheet of Glad Press’n Seal ®

Note: briefly rub with the flat of the hand to seal the plastic to the tops of the vial.

11. Invert a cardboard tray (without dividers) onto the sealed vials

Note: This makes the vials easy to handle without disturbing the plastic

12. Store each tray of sealed vials at 4°C

Helpful Hints

· To remove clumps, use a hand mixer, or press out larger lumps with the back of a large spoon

· Problematic food is often simply dry food. Seemingly small changes in the cooking process can make a significant difference in the quality of the food if those changes result in increased water loss. Take special care in this regard, especially in dry climates.

· Recipe can be scaled up by using multiple Nutri-Fly packets (increase the volume of dH₂O and propionic acid accordingly)

· If new to Nutri-Fly start small on your first batches. Before combining multiple packets, start with one to gain experience and a comfort level and gradually move to larger batches.