Taste Preference Assay: A Method for Measuring Feeding Behavior in Drosophila

- To perform the taste preference assay, use a chamber, for example, a Petri dish divided into equal sections. If measuring the choice between two solutions of different tastes, label one in red and the other in blue using tasteless food coloring agents. Then place equally spaced drops of each solution along the edge of the dish across alternating sections.

Now add anesthetized and previously starved flies to the middle of the chamber and cover the dish. Perform the experiment in the dark to exclude potential color bias, and incubate at 25 degrees Celsius over a set time period. When given a choice between two solutions, more subjects prefer to consume solutions whose taste is more attractive, for example, sweet, while avoiding aversive options such as bitter solutions. Stop the experiment by moving the chamber to a freezer.

To measure feeding behavior and taste preference, compare the number of flies with different colored abdomens. In the example protocol, we will see a demonstration of the taste preference assay that measures the choice between various sucrose solutions.

- To begin the experiment, saturate a cotton ball with water at the bottom of a standard fly vial. Next, coll