The purpose of this study was to explore magnetic particle imaging (MPI), which directly detects superparamagnetic iron oxide nanoparticles (SPIOs) as a novel technique for tracking dendritic cells (DCs). DCs were labeled using Vivotrax, a commonly used MPI-SPIO, and Synomag-D, a tailored MPI-SPIO, with and without transfection agents. Vivotrax with TAs showed high levels of extracellular iron, overestimating iron content and cellular sensitivities. The use of TAs improved cellular sensitivity of Synomag-D to as few as 6k cells with 1min 2D images. Signal from 250k and 25k cells could be resolved at a distance of 2cm with 3D imaging.