DCs are still able to engulf particles after the fusion procedure. DCs were treated with PEG or underwent electrofusion, while control cells were untreated. All samples were incubated with Fluoresbrite™ Carboxylated Microspheres (size 1.58 µm) for 150 min and analyzed by flow cytometry (left). Only those cells that had phagocytosed more than 2 beads were counted as positive (percentage indicated). As a control, a second set of samples was pretreated with 15 µM cytochalasin D prior to incubation with the microspheres (right). The fluorescence peak with an intensity of up to 10¹ represents DCs that have not internalized beads, as determined by a control sample (data not shown). One representative experiment is shown.