Fig. 3: Component calibration for precise stimulation and measurement between wells.

a Calibration of photodiodes must be performed first in order to use photodiodes to calibrate the LED components. Photodiodes are calibrated by using a uniform white light source to illuminate all wells with the same light intensity. b Blue LEDs are calibrated with the photodiodes in a fully assembled oPR, using an empty 96-well plate and no emission filter. c OD LEDs are calibrated in a fully assembled oPR with an equal volume of LB in each well to to account for light refraction through the medium. This calibration should be performed at the start of each experiment using the “Calibrate OD” function found in the GUI. d UV LED calibration is performed in a fully-assembled oPR with an equal volume of diluted lucifer yellow dye in each well (40 µg/mL shown here). Calibration is performed by adjusting LED intensity to normalize variation in the measured emission intensity of the dye. In all cases, calibration reduced variation between wells to CV = 1–3%.