Product Code Pack Size Sterling Euros Dollars      50059  250mg  £80  €124  $164   3´,4´-Dihydroxyflavone-4´-β-D-glucopyranoside sodium salt DHF-glucoside sodium salt; 3´,4´-Dihydroxyflavone-4´-beta-D-glucopyranoside sodium salt CAS: 517892-03-4 MF: C21H19NaO9 MW: 438.40   Substrate producing highly visible, localised, black or dark brown colonies when used in conjunction with an iron salt. This dark colour is able to mask the colour formed by indoxyl substrates such as X-Gal (70045) when incorporated into the same medium. Can also be used to produce discrete yellow colonies in the presence of aluminium salts.   Picture : Intense black colonies of beta-glucosidase-positive Enterococcus faecalis stand out sharply from the cream colonies of Staphylococcus aureus which do not express this enzyme, even where the colonies are practically coincident.       Protected by Glycosynth patents: European Patent  1438423 and US Patent 7,531,646.   For use only in internal research conducted by the purchaser. No rights under the aforementioned patents are conveyed which permit the resale, transfer, or use for purposes other than research. Rights under the aforementioned patents, for purposes other than internal research, may be obtained by contacting Glycosynth Ltd.