Figure 1.

Step-wise illustration of endotracheal delivery method (I.T). Endotracheal intubation was carried out in a C57BL/6 mouse anesthetized with 2% isoflurane and oxygen at a flow rate of 2 liters/min using an illuminated otoscope, a 22G blunt-tip intravenous catheter, a 45⁰ C-angled intubation stand, a P200 pipette with P200 tip and a P200 pipette with extended length gel loading tip (A). Unconscious mouse breathing at a respiration rate of 30 breaths per min was placed by hooking its upper incisor over a string attached to the intubation board. An otoscope was placed into the mouth and the vocal cord was visualized (B). A 22G blunt-tip intravenous catheter attached to a syringe was then inserted into the trachea (C). The syringe was then replaced with a P200 pipette attached to a p200 tip containing water and the movement of water in the tip during breathing was confirmed to affirm the insertion of catheter into the trachea (D). Next, P200 pipette attached to an extended length gel-loading tip loaded with 50 μL AdHu5Luc or vaccine was inserted into the catheter and allow to inhale by the mouse (E).