Easy calibration of the Light Plate Apparatus for optogenetic experiments

Optogenetic systems use genetically-encoded light-sensitive proteins to control and study cellular processes. As the number and quality of these systems grows, there is an increasing need for user-friendly and flexible hardware to provide programmed illumination to cultures of cells. One platform which satisfies this need for a variety of optogenetic systems and organisms is the Light Plate Apparatus (LPA), which delivers a controlled light dose to each well of a 24-well plate. Experimental reproducibility requires appropriate calibration to produce accurate light doses within individual wells of the LPA and between LPAs. In this study, we present an easy and accurate method for calibrating the LPA. In particular, we: • developed a 3D printed adaptor and MATLAB code to allow rapid measurement of irradiance produced by the LPA and subsequent calibration; • provide appropriate code and methodology for generating a standard curve for each LPA; • demonstrate the utility and accuracy of this method between users and LPAs.