Image it fx reagent

Paraffin embedding and sectioning was performed by the Moores cancer center histology core at UCSD. For OCT embedding, tissue biopsies were first fixed with 4% PFA for 2 hours then cryoprotected by sucrose for 48 hours prior to being embedded in OCT compound and stored in −80 ⁰C. Histological analysis was performed using either paraffin sections or frozen sections by Hematoxylin-Eosin (H&E) staining. Collagen was stained by the Richard-Allan Scientific Gomori Trichrome green collagen staining kit (ThermoFisher Scientific, Waltham, MA, USA). Elastic staining (Thermo Fisher Scientific, Waltham, MA, USA) and hydroxyproline assay (BioVision) were performed on human or mouse tissues according to manufacturer’s instructions. For IHC, fixed and permeabilized tissue sections were blocked with Image-iT FX reagent (invitrogen) before incubating with primary antibodies followed by appropriate 488- or Cy3-coupled secondary antibodies. Nuclei were counter-stained with DAPI. All images were taken with an Olympus BX41 microscope (widefield) or Zeiss LSM510 confocal microscope as indicated.