4-Methylumbelliferyl-beta-D-glucuronide, dihydrate, min. 99 %, p.a., Molar mass (M) 388,33 g/mol, Storage temp. -20 °C, CAS No. [881005-91-0], EG-Nr. 228-186-0, Empirical formula C16H16O9 · 2 H2O