Figure 6.

Quantify fluorophore brightness to convert intensity to concentration

(A) Diagram of setup for imaging reference slides: FluidFM controller with canticlip holder attached but no probe.

(B) Two reference slides, with and without coverslip spacer to create a wider, thinner drop (left) or narrower, taller drop (right). Labeled with drop concentration, volume, and area. Area border drawn and measured in ImageJ. Drop volume and area used to calculate drop thickness.

(C and D) Results of imaging calibration slides with 40x (C) and 10x (D) objective. Plots of drop concentration ∗ thickness vs. modal intensity. Linear fit in GraphPad Prism to determine conversion factor needed to fit the model.