Figure 1: PMA and cytochalasin D treatment enhanced Ca-apatite mediated transgene delivery in T-lymphocytes. DNA/carbonate apatite particles were prepared by mixing 3 μl of 1 M CaCl2 and 2 ug of reporter plasmid DNA in presence or absence of 1 μg of PI in 1 ml of fresh serum-free HCO3--buffered DMEM medium (pH 7.5), followed by incubation for 30 min at 37°C and mixing with 10% FBS and subsequently with PMA (10 nM), cytochalasin D (1 μM) or both. The particle suspension was added onto the cells in each well immediately after the old RPMI medium had been removed from the well. After incubation for 4 h, the cells were washed with 0.5 mM EDTA in PBS before observation of PI-labeled DNA in cell cytoplasm by a fluorescence microscope. Bar indicates 50 μM.