Fluorogenic Substrates

4-Methylumbelliferyl-beta-D-glucuronic acid methyl ester is a chromogenic substrate for β-glucuronidase. It is used in diagnostic applications and as a substrate in enzyme kinetics experiments. 4-Methylumbelliferyl-beta-D-glucuronic acid methyl ester has fluorescence properties that allow it to be detected by chemiluminescence and bioluminescence.

4-Methylumbelliferyl propionate is a fluorogenic substrate for esterase. After enzymatic cleaveage, free 4-methylumbelliferone (also known as hymecromone) is released, exhibiting blue fluorescence upon excitation with UV light. The strongest fluorescence of 4-methylumbelliferone requires deprotonation of the hydroxyl group (thus requires alkaline pH), with a maximal fluorescence intensity obtained with excitation at 350 to 370 nm and emission at 440 to 470 nm. The use of 4-methylumbelliferyl propionateas a substrate for measuring the esterase activity is used for esterase deficiency screening assays.

Resorufin N-acetyl-b-D-glucosamine is fluorogenic substrate for N-acetyl-beta-D-glucosaminidase (NAG).

Living cells of Escherichia coli can be reliably detected with media that contain a chromogenic or fluorogenic substrate for beta-glucuronidase (also termed β-D-glucuronidase), an enzyme that occurs almost exclusively in E. coli. RUG®, Resorufin-beta-D-glucuronic acid methyl ester is a highly sensitive chromogenic and fluorogenic indicator for E. coli. After removal of the methyl ester group by unspecific hydrolysis, orange colored product is cleaved by beta-glucuronidase in liquid media or on agar plates and yields an intense pink color. Red fluorescence is obtained upon excitation at 560-570 nm.Formally ER175455.

Methyl 4-methylumbelliferyl hexyl phosphonate is a lipase suicide inhibitor that is a fluorogenic substrate for lipases which upon enzymatic action, binds irreversibly to the lipase and inactivates it. The substrate can be used for the determination of active sites in lipases and the fluorescent signal can be detected at Ex 363 nm and Em 465 nm.

5-(Pentafluorobenzoylamino)fluoroscein di-b-D-galactopyranoside, commonly referred as PFB-FDG or PFB-FDGal, is a cell-permeable enzyme substrate for β-galactosidase used in live cell imaging assays. After cleavage, 5-(pentafluorobenzoylamino)fluorescein (PFB-F) is released, generating a green fluorescence (Em ~520 nm)) of a higher intensity than fluorescein. Its main use is for bacterial detection (e.g. E. coli LacZ assays), but also for flow cytometry analytical assays.

For fluorogenic detection of caspase 3

Maltotetraose 2-aminobenzamide is a chemiluminescent substrate that emits light in the presence of certain oxidizing agents. It provides high quality and environmental testing, as well as staining and ligand capability. Maltotetraose 2-aminobenzamide is used in diagnostics to identify bacteria and other microorganisms. Maltotetraose 2-aminobenzamide can be used for the detection of bacterial colonies on agar plates using a fluorogenic substrate, or for the detection of fungi using a chromogenic substrate. Maltotetraose 2-aminobenzamide is also used as an enzyme substrate in food testing or conjugate with enzymes for bioluminescence.

4-Methylumbelliferyl-phosphoethanolamine is a phosphorylated substrate that can be used in the detection of enzymes such as alkaline phosphatase, esterase, and lipase. This compound has been shown to be a fluorescent and chromogenic substrate for many diagnostic purposes. 4-Methylumbelliferyl-phosphoethanolamine is also used as a fluorogenic substrate for chemiluminescent reactions that are found in culture media and environmental testing.