Fig. 2.

Efficiency and stability of PTD5 labeling of A-NK carrier cells. A-NK cells were incubated with FITC-conjugated PTD5 (black histogram) and PTD-R peptides (black circle) at 12.5 μM for 2–3 h. Control A-NK cells (black triangle) were incubated with media alone. FITC labeling of the A-NK cells was measured by flow cytometry immediately at 0, 24, 48, and 72 h after labeling. The percentage of FITC-positive A-NK cells was analyzed from separate experiments. The data were expressed as mean ± SD