Abstract 2128 Quantifying Acid Tolerance in Human Cells using a Next-Generation Ratiometric pH Sensor

Intracellular pH regulation is essential for cellular function and disease progression, particularly in cancer biology, where disrupted pH homeostasis contributes to tumorigenesis, metastasis, and resistance to therapy. While effective, traditional genetically encoded pH sensors, such as pHluorin2, do not span the full range of pH values needed to model the acidity of cancer cell microenvironments or acidic organelles, such as lysosomes. To address this unmet need, we developed and validated ORION (ratiOmetRIc prOton seNsor), a novel Bioluminescence Resonance Energy Transfer (BRET)-based pH sensor with a heightened dynamic range spanning pH 4.0–8.0.