We are having some problems when culturing mouse colon organoids in matrigel drops.

We first achieve to obtain well formed colon organoids (first photo) but, after a few days, the ones that are closer to the border of the matrigel start to fuse with it and end up dying (second photo).

When too many organoids have escaped from the matrigel, the ones that are still inside also end up dying.

Also we have tried turning upside down the plate before the matrigel fully polymerizes, to avoid organoids going to the border of the drop, but it still happen the same.

We have not seen photos of organoids escaping like this in matrigel drops. So we wonder if this is normal or what can we do to avoid it.

Thank you in advance.