Incucyte® pHrodo® Bioparticles® are sterile fluorogenic reagents ideally suited to a simple mix-and-read, real-time live cell quantification of phagocytosis. The unique pHrodo®-based system exploits the acidic environment of the phagosome to quantify phagocytosis. As Incucyte® pHrodo® Bioparticles® residing in the neutral extracellular solution (pH 7.4) are engulfed by phagocytes and enter the acidic phagosome (pH 4.5 – 5.5), a substantial increase in fluorescence is observed. Application of Incucyte® pHrodo® Bioparticles to non-phagocytic cells yields little or no fluorescent signal. With the Incucyte® ZOOM® integrated analysis software background fluorescence is minimized. These fully sterilized reagents have been validated for use with the Incucyte® live-cell analysis system and enable real-time evaluation of phagocytic regulation by pharmacological agents as well as genetic and environmental factors.