Denatured collagen standard for the Biocolor S2000 Sircol Insoluble Collagen (Bovine) colorimetric assay. 1mg/ml (3x5ml). A sterile solution of cold, water-soluble denatured collagen from bovine skin, stored in 0.1M acetic acid within a sealed vial. Once opened, store at 4 degrees C, discard if the solution becomes turbid.