4.2.2 Characterization.
Agarose gel electrophoresis. A 1% (w/v) agarose gel was prepared
with EtBr. A total of 5 μL prepared
Td mixed with loading buffer was loaded and run at 95 V for 35 min. To
identify the Td with ASOs, a 2% (w/v) agarose gel was used.
AFM imaging. All samples were diluted to 2.5 nM in TM buffer
(12.5 mM Tris, 5 mM MgCl2). Then, 10 μL of Td was
dropped onto freshly cleaved mica and incubated for 5 min to allow
strong absorption onto the surface. Then, the mica was rinsed using
filtered deionized water and gently dried with compressed nitrogen.
Next, the samples were scanned in tapping mode on an Agilent 5500 SPM.
Dynamic light scattering. A 2 μM solution of Td was prepared
based on the above-mentioned protocols and then diluted to 0.2 μM with
ultrapure water. After passing through a 0.22 μm filter, samples were
analyzed by a Malvern Zetasizer Nano ZS to measure the hydrodynamic size
and size distribution.
TEM. LP-Td was dropped on a grid and incubated for 4 min, then
remaining solution was absorbed by filter paper. The TEM images were
obtained by JEM-2100Plus with 80 kV.