Figure 4.

Microfluidics and microscope imaging set up

(A) Reservoirs are held over the device with a tubing rack stand. Tubing from the reservoirs is connected either directly into the device or through the 3-way actuated valve for fluidic control. The device is positioned above the objective on the microscope.

(B) Close up image of the microfluidic device with all tubing attached in the inlets, worm loading (WL) port, and the outlet.

(C) Schematic of the 20 x 20 mm microfluidic device. Black lines represent 70 μm tall fluid channels. Stimulus (Stim) and Buffer (Buf) streams flow continuously, whereas only one control fluid inlet flows at any time.

(D) Actuating the 3-way valve directs control fluid to the control1 inlet and the stimulus into the arena (left). Otherwise, control fluid enters at the control2 inlet and buffer enters the arena (right). Proper flow balance is shown, with fluorescein dye used as the stimulus fluid. Note that some of the fluid entering the arena also bypasses it via the upper and lower curved channels. These streams should be narrow and have equal width in the upper and lower channels. Adjust reservoir heights as needed.