3,4-Cyclohexenolesculetin (CHE Substrates)

3,4-Cyclohexenoesculetin (CHE) based chromogenic substrates are a range of substrates that rely on a highly coloured chelate forming between the released aglycone and a metal ion. CHE based substrates allow the growth of both gram-negative and gram-positive bacteria. When used in the presence of Fe3+ the resultant catechol-iron chelate forms an insoluble black precipitate that is tightly localised to bacterial colonies, allowing the possibility of CHE substrates being used in mixed cultures. CHE beta-D-galactopyranoside (product code 75045) is an autoclavable chromogenic substrate for beta-galactosidase activity. CHE-Gal is an alternative to X-Gal or other indoxyl substrates and yields a unique, strong black colour strictly confined to colonies. CHE beta-D-glucopyranoside (Product code 75059) has been shown to be superior to esculin for the detection of Listeria spp. In food samples