Rabbit anti mouse collagen 1 polyclonal antibody

For immunohistochemical staining, media was first removed from the gels. The gels were then fixed with 4% paraformaldehyde in serum free DMEM at 37°C for 30 – 45 minutes. Gels were then washed 3 times in PBS containing calcium (cPBS), and incubated overnight in 30% sucrose in cPBS at 4°C. The gels were then placed in a mix of 50% of a 30% sucrose in cPBS solution, and 50% OCT (Tissue-Tek) for several hours. Then the media was removed, the gels were embedded in OCT and frozen. The frozen gels were sectioned with a cryostat (Leica CM1950) to a thickness of 30 – 100 μm, and stained following standard immunohistochemistry protocols. The following antibodies/reagents were used for immunohistochemistry: Rabbit-anti-mouse Collagen I polyclonal antibody (Abcam, cat. # 34710), YAP antibody (Cell signaling, cat. # 4912), Paxillin antibody (Abcam, cat. # 32084), β1 integrin antibody (BD Biosciences, cat. # 550531), Prolong Gold antifade reagent with DAPI (Invitrogen), AF-488 Phalloidin to stain actin (Invitrogen), Goat anti-Rabbit IgG AF 647 (Invitrogen). The Click-IT EdU cell proliferation assay (Invitrogen) was used to identify proliferating cells.