 Sometime in mid-March, an "unnamed pet food company" reported to Cornell they had discovered an industrial chemical used in plastics manufacture, melamine, in internal testing of wheat gluten samples.By 21 March, it became clear the common factor was in the wheat gluten used to thicken the gravy in the "cuts and gravy" style wet foods.By 27 March, Cornell had confirmed the presence of melamine in the originally recalled pet foods, the wheat gluten used in their manufacture, the cells of the dead pets, and in the urine samples from dead and sick pets.