Description_x000D_ Application_x000D_ Gum guaiac is a tree resin and crude source of 2,5-di-(4-hydroxy-3-methoxyphenyl)-3,4-dimethylfuran (α-guaiaconic acid). The phenolic α-guaiaconic acid acts as a colorimetric peroxidase substrate. When reacted with an organic or inorganic oxidizing agent, the α-guaiaconic acid is oxidized to a blue-colored quinone. The guaiac reaction has been used to detect trace amounts of heme from hemoglobin in the presence of peroxide._x000D_ The Nobles test can be performed using 67% (w/v) gum guaiac diluted in 96% ethanol to analyze the level of extracellular oxidase production_x000D_ Packaging_x000D_ 1 kg in poly bottle