2.18. Hydrodynamic injection (HDI)

The hydrodynamic injection was performed as previously described.³⁰ Briefly, 16 μg plasmids were injected into the tail vein of C57BL/6 mice (6-week old, male) in 2 mL PBS (almost equivalent to 8% of the mouse body weight) within 5 seconds. Then sera were collected at 3, 5 and 7th days post-injection. C57BL/6 mice were purchased from the Department of Laboratory Animal Science, Peking University Health Science Center. Animals were housed in specific pathogen-free barrier facilities. All experiments in mice were conducted according to institutional guidelines of Peking University Health Science Center.