A method for detection of beta-D-glucuronidase activity in a sample that comprises the steps of (i) providing a glucuronic acid ester compound of the general formula (I) wherein R1 is a C1-4 alkyl group, OR2 is a dye moiety, which is liberated after cleavage of the glycosidic bond; (ii) contacting said glucuronic acid ester compound with a material of said sample exhibiting hydrolytic activity towards glucuronic acid esters, thereby removing R1 and thus forming a sample containing an indicator compound suitable for the detection and/or measurement of beta-D-glucuronidase activity, and (iii) using said indicator to perform an assay requiring detection or measurement of beta-D-glucuronidase activity.