Selection for the optimal TRAIL expression vectors in HEK293T cells. HEK293T cells were transiently co-transfected with either pCMV6 (A) or pLOC (B) plasmid using Fugene 6 (3:1 transfection reagent to DNA ratio) and images obtained by fluorescence inverted microscopy (magnification: 10X). Significantly higher percentage of fluorescence cells after pLOC plasmid transfection compared to pCMV6 for both the empty vector (EV) and TRAIL encoded plasmid as quantified by FACS, (C). Expression of TRAIL transcript was confirmed by quantitative RT-PCR and GAPDH was used as internal control for the analysis (D). Plasmid map for the relevant vectors were also depicted (E; **p < 0.001; t-test).