Table 1.

Troubleshooting table.

Step	Problem	Possible reason	Solution
17	Movement of the graft during imaging	Movement of the head because the head holder is not properly fixed	Fix the clamping of the head holder
		Movement of the eye during normal breathing	Adjust the eye stabilizer carefully
		Gasping of the mouse	Make sure that the airflow of the anesthesia unit and isoflurane levels are set properly
18B(iii)	No fluorescence can be detected in the blood vessels	Tail vein injection failed	Repeat tail vein injection
		Excitation and emission settings are wrong	Adjust excitation and emission settings
		Blood circulation to the eye is disrupted because of false setting of eye stabilizer	Adjust the position of the eye stabilizer
18D(ix)	Perfusion does not work	Air bubbles block the pipettes, capillary holder or tubing	Make sure that there are no air bubbles in the tubing, capillary holders or capillaries prior to the experiment
		Dirt blocks the pipette tips	Be sure to clean the pipettes after beveling, right before the experiment