Revvity pHSense Eu Fab Anti-Mouse IgG2, 2 x 96 wells

pHSense Eu Fab reagent is a covalently europium-labeled, pH-sensitive Fab fragment designed to monitor antibody or anti-drug conjugate (ADC), as well as receptor- and membrane protein-mediated internalization in real time. It binds with high affinity to the Fc region of test antibodies, particularly mouse IgG2 subtypes, and remains minimally fluorescent at neutral extracellular pH (≥7). Upon internalization, the Fab-antibody complex encounters increasingly acidic intracellular compartments such as early and late endosomes and lysosomes, where the europium signal becomes progressively stronger. This novel pH sensitive europium complex is compatible with a time-resolved fluorescence (TRF) detection, effectively eliminating most fluorescence background and significantly enhancing the signal-to-background ratio. Its unique photophysical properties enable simple and robust no-wash detection of receptor-mediated endocytosis of antibodies in plate-based assays with live cells.