Fig. 1
Calcium chloride facilitates the condensation of plasmid DNA with HIV-Tat-derived peptide into nanoparticles. (A) Agarose electrophoretic mobility assay. pDNA (pGL3 plasmid) were labeled with (2) or without (1) DiYO1. Labeling ratio was 1:5 (D: BP). M: DNA ladder. (B) Gel retardation assay. Lanes 2–6: Tat/pGL3-Ca2+ nanoparticles; lanes 7–11: Tat/pGL3-Ca2+-DiYO1 nanoparticles; N/P ratios between Tat and pGL3 were 0, 1, 5, 10, 20, respectively. (C) DNase I protection assay. Tat/pGL3-Ca2+ nanoparticles treated with (lanes 7–11) or without (lanes 2–6) DNase I. N/P = 0, 1, 5, 10, 20, respectively. (D) Size distribution of Tat/pGL3-Ca2+ nanoparticles determined by DLS. N/P = 10. (E) AFM image of Tat/pGL3-Ca2+ nanoparticles. Scale bar: 1 um. (F, G, H) TEM imaging of pGL3, Tat/pGL3 and Tat/pGL3-Ca2+ nanoparticles negatively stained with uranyl acetate. N/P = 10