Hi Thomas,

An under agarose assay could work for you. I made good experience by coating the plate with fibronectin (10µg/ml) in PBS at 37°C for 1h and then casting the agarose onto it. You can then inject the cells with a gel loading pipette gently under the agarose and then image spontaneous migration. Hopefully this helps - I can also provide you with an protocol if you drop me a message.

Best,

Philippe