I'm working with human foreskin fibroblasts (HFF1) in collagen 3D cultures (collagen solution type I, ultrapure, bovine from Sgma-aldrich) using 48 well plates.
I tried mixing different cell numbers in the collagen solution but after forming the gel (at 37oC for an hour) I add the celll medium and the next day the gel seems to have dissolved or contracted to a small, white, round chip.
Any idea to what I am doing wrong?
Happened to anyone? Any solution?