Two independent primary mouse fibroblast isolations FB1 (black) and FB2 (grey) were cultured in collagen gels for 3 days before being released by collagenase treatment and plated on TCP for 4 days (triangle). Controls were kept on TCP for 3 days before plating (circle). Fold increase in confluency 24 hours after plating of collagen gel released cells and cells kept on TCP is shown (n= 3 technical replicates). 