When designing FLIC our original intention was to use it to monitor food preference, but we soon found that it had other uses, including long-term measurements of feeding activity. Our initial solution for this problem (which you can see at the end of the “Experimental Setup” tutorial) was a reservoir that was functional but finicky and took a significant amount of time to set up. We’ve now improved upon this idea, creating a reservoir that is faster to set up, avoids the problems of air bubbles, and maintains food levels longer, easily lasting through the weekend without needing to be refilled.
The new system consists of a small cell culture flask, which we use as the new reservoir, and a slightly modified base. We drill holes in the reservoir and base, then use a luer-lock system to attach the new reservoir to the wells from the side instead of the top. The wider surface area of the new reservoir increases the length of time that food height is maintained at acceptable levels, and by attaching it from the side instead of the top, air bubbles in the line (which can cause overfilling and make setup more difficult) don’t typically occur. For short-term experiments, these attachments can just be closed off with a cap and the FLIC can be used as normal.
If you have any questions or suggestions about the new reservoir system, feel free to let me know at (firstname.lastname@example.org).