Carbon coated copper grids 200 mesh

Morphological examinations of the optimized LPHNPs (F3) and the uncoated NPs (F1) were carried out through TEM. Briefly, one mL of the NP suspension was diluted ten times with DW. A drop of the diluted suspension was put on the surface of carbon-coated copper grids (200 mesh; Science Services; Munich, Germany). The extra material was subsequently detached using a filter paper to leave a thin film that was extended over the holes and left for 10 min at room temperature to dry completely before examination^{18 (link)}. Capture as well as image analysis were done by digital micrograph and soft imaging viewer software.

Carbon-coated copper grids, 200 mesh (Science Services, Munich, Germany) were treated with oxygen plasma (Zepto, Diener electronic GmbH, Ebhausen, Germany). After this, 3 µL of precipitation-purified rAAV sample [25 (link)] was applied to the grid and incubated for 2 min. Excess liquid was drained off, the grid was dried at room temperature and washed with three drops of distilled water. Negative staining was performed using 3 µL 2% (v/v) uranyl acetate replacement stain (Science Services) for 30 s. Excess liquid was drained off and grids were dried before channeling the sample into the microscope. rAAVs were visualized with a CM100 (PW6021) instrument (Philips, Hamburg, Germany) with an acceleration voltage of 80 kV. Images were analyzed using the Soft Imaging Viewer (Olympus, Münster, Germany) and ImageJ [50 (link)].