Designing a Single Protein‐Chain Reporter for Opioid Detection at Cellular Resolution

Mu-opioid receptor (MOR) signaling regulates multiple neuronal pathways, including those involved in pain, reward, and respiration. To advance the understanding of MOR's roles pain modulation, there is a need for high-throughput screening methods opioids vitro high-resolution mapping brain. fill this need, we designed characterized genetically encoded fluorescent reporter, called Single-chain Protein-based Opioid Transmission Indicator Tool MOR (M-SPOTIT). M-SPOTIT represents new unique mechanism reporter design can detect activation, leaving persistent green fluorescence mark image analysis. showed an opioid-dependent signal to noise ratio (S/N) up 12.5 was able as fast 30-second opioid exposure HEK293T cell culture. Additionally, it S/N 4.6 culture detected fentanyl with EC50 15 nM. will potentially be useful detection cultures cellular-resolution vivo. M-SPOTIT's novel used platform other G-protein-coupled receptor-based sensors.