Figure 1: Schematic of freezing techniques utilized. (A) Tissue sections were embedded in OCT within a cryo-mold, which was then floated on LqN2-cooled isopentane. The isopentane should touch the bottom and sides of the cryo-mold, but should not come directly in contact with the OCT, as this will result in the formation of bubbles within the block. (B) To optimally freeze skeletal muscle, a wooden dowel is topped with 10% (w/v) gum tragacanth in PBS. The extracted tissue is then partially embedded in this adhesive, with the part to be cut extending above it. The dowel is inverted and submerged in LqN2-cooled 2-methylbutane to snap-freeze the tissue.