We are using 3 day-old-flies (half of the experimental flies have their wings clipped, and half don’t).

To know if they have preferences for darkness or light (phototactic or non-phototactic response) we are following this protocol:

1. Clip wings of half of the flies.

2. Let flies recover for 1 day (at 25°C, faster recovery).

3. Put the flies in the T-maze (entrance tube) and let them adapt themselves to the machine and the darkness for 10 minutes.

4. Move the flies into the elevator (the mobile part of the T-maze), and let them stay there for around 1 minute.

5. Move the flies to the bottom of T-maze (taking down the elevator).

Now they will have to make a decision between two different tubes: one is completely dark, and the other one has a LED in the bottom/is entirely transparent.

We are using different LEDs:

White LEDs

Yellow LEDs

Green LEDs

6. Wait for 30 seconds for the flies to make their decision, and lock them in the tubes that they have chosen (taking up the elevator).

7. Count the flies under the magnifying glass, after anesthetize them with CO₂.