Incorporation of propidium iodide (PI) and FITC-conjugated anti-CD3 MoAb into electropermeabilized resting and activated human neutrophils.

Intact (Control) and electropermeabilized (Elect.) neutrophils were incubated with 10 μg/mL PI or 24 μg/mL FITC-conjugated anti-CD3 MoAb for 3 minutes at room temperature. The electropermeabilized cells were preincubated with 5 μg/mL cytochalasin B for 5 minutes at 37°C and subsequently incubated for 10 minutes at 37°C in the absence (Elect. [15 minutes]) or in the presence (Elect. [Act.]) of 1 μmol/L Ca⁺⁺ and 50 μmol/L GTP-γ-S. Then, intact and electropermeabilized neutrophils were analyzed for anti-CD3 MoAb and PI incorporation by flow cytometry as described in “Materials and methods.” The results shown are representative of 3 independent determinations.