Measure arrestin signaling kinetics in real time with the live cell, fluorescent Borealis arrestin - PAR2 assay. Add the unmodified PAR2 receptor and Borealis sensor to cells and measure robust signals the next day on an automated plate reader or fluorescence imaging system. This assay is genetically encoded and packaged in BacMam for efficient transduction in most cell types - including uniform and near 100% efficiency in HEK293 cells as well as expression in many primary or iPSC-derived cells. The kit includes the arrestin sensor BacMam, PAR2 BacMam, 500mM sodium butyrate in H2O, and a positive control receptor and agonist (AT1R BacMam and 5mM Angiotensin II in H2O). 30mL and 60mL sizes are available as well, as are Borealis kits for several other receptors. Other Montana Molecular tools including the DAG and Calcium sensors can be used alongside this assay.