To quantify the expression level of GFP, total RNA was extracted from the respective samples and subjected to RT-qPCR. The RT-qPCR results confirmed the very low expression of the GFP in the samples infiltrated with TRBO-GFP-PEI 30 -SWCNT complex (Fig. ). To explore these results further, a 10.6-kb non-viral binary vector (pMDC43) harboring a GFP expression cassette was delivered via both Agrobacterium and PEI 30 -SWCNT, and leaf sections were subjected to confocal imaging 3 days post-infiltration. Confocal microscopy analysis confirmed even less expression of the GFP from a simple binary vector when delivered via PEI-SWCNT (Fig. ).