Supplement Summary Supplement application for a CLARIOstar Plus microplate reader with six detection modalities This is an administrative supplement application for the purchase of a CLARIOstar Plus multi-mode microplate reader from BMG Labtech. The CLARIOStar is a high-performance, medium-throughput instrument with environmental control that provides a unifying solution to the six detection modalities used routinely in our NIGMS-funded work: UV/Vis absorbance, fluorescence, luminescence, fluorescence polarization, time-resolved fluorescence and ALPHA assays. I am requesting the CLARIOStar for the following reasons. (1) It will replace a broken, decade-old microplate reader that is used in my laboratory for Hedgehog and WNT signaling assays central to all the projects supported by my NIGMS MIRA (R35 GM118082) award. (2) It will advance the goals of the research program outlined in my 2021 NIGMS R35/MIRA renewal by enhancing our capability to perform live cell assays with environmental control, protein-protein and small molecule-protein interaction measurements, and kinetic measurements, all with ten-fold higher speed, sensitivity and dynamic range compared to our previous instrument. (3) A microplate reader with these capabilities is not presently available at Stanford on a cost-effective basis given our intensive usage needs. The Biochemistry Department at Stanford will support this purchase with both funds for instrument service and space to house the microplate reader. In summary, the CLARIOstar will accelerate NIGMS-funded research projects in my laboratory and provide cutting-edge training in assay design and optimization for trainees that work on these projects.