5-Dodecanoylaminofluorescein di-beta-D-glucuronide

Non-fluorescent reporter protein substrate. This fluorogenic beta-glucuronidase substrate releases the highly fluorescent dye 5-dodecanoylaminofluorescein (Spectral data: lambdaex=490nm, lambdaem=520nm) in direct correlation with enzyme activity. The substrates can penetrate the cell membrane under physiological conditions and forms a non-toxic green fluorescent product that is well retained in viable cells and which allows sorting and cloning of the cells and monitoring of cell development in vitro and in vivo. The colorless and lipophilic substrate enters the cells by embedding in the outer layer of the cell membrane as a glycolipid and then transferring to the inner membrane by a 'flip-flop' mechanism. Once inside the cell, the substrate is cleaved by beta-glucuronidase, generating the green fluorescent enzymatic hydrolysis product 5-dodecanoylaminofluorescein, which is retained in the cell membrane because of its lipophilic hydrocarbon chain, and allowing histochemical, spectrophotometric and fluorometric measurements of GUS gene fusion expression. This substrate has been used in beta-glucuronidase (GUS) gene expression kits.