Other Enzyme Substrates

Red-β-D-GlcU (5-Bromo-6-chloro-3-indolyl-β-D-glucuronide,cyclohexylammmonium salt), also known as Magenta-β-D-GlcA; is similar to X-GlcU, but the product of the substrate is a red (λ_max 565 nm) precipitate, which is easier to detect against the background of plant cells.

Resazurin (also known as alamarBlue™) is the N-oxide of the fluorescent dye resorufin and is useful for detecting reductive activities in cells. It has been widely used for measuring cell proliferation (1,2) and mitochondrial metabolic activity. Resazurin itself is non-fluorescent until it is reduced to the highly red fluorescent resorufin (λ_Ex/λ_Em: 563/587 nm).

High purity resorufin that can be used as a standard for enzyme substrates whose end product is resorufin.

Rose-β-D-Gal (6-Chloro-3-indoxyl-β-D-galactopyranoside) is a chromogenic substrate for β-galactosidase. The product is similar to X-gal, but generates an intense pink colored precipitate (λ_max ~ 540 nm) on enzymatic hydrolysis.

Rose-β-D-GlcU (6-Chloro-3-indolyl-β-D-glucuronide,cyclohexylammonium salt), also known as Salmon-β-D-GlcUA, is similar to X-GlcU, but the product of the substrate is a rose-colored (λ_max ~ 540 nm) precipitate, which is easier to detect against the background of plant cells.

X-β-D-cellobioside (5-Bromo-4-chloro-3-indolyl-beta-D-cellobioside) is a chromogenic substrate for β-cellobiosidase. Enzymatic cleavage of the substrate generates a dark blue-colored precipitate.

X-gal (5-Bromo-4-chloro-3-indolyl-β-galactopyranoside) is the most widely used chromogenic substrate for β-galactosidase. Enzyme hydrolysis of the substrate yields a dark blue colored precipitate (maximum absorbance 615 nm).

Alternate name: BCIG. X-GlcU (5-Bromo-4-chloro-3-indolyl-β-D-glucuronide, cyclohexylammonium salt) is a chromogenic β-glucuronidase substrate widely used for monitoring E. coli contamination in food (such as meat, dairy products and shellfish, etc) and water, and for the detection of GUS gene expression in plants.

X-GlcU, Na ( 5-Bromo-4-chloro-3-indolyl-β-D-glucuronide, sodium salt), also known as X-GlcA, Na, is similar to X-GlcU, CHA, but has better water solubility.

XTT (2,3-Bis-(2-Methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide, disodium salt) is a tetrazolium derivative used widely in cell viability and proliferation testing. The material is readily reduced in viable cells to a highly water-soluble orange colored product (λ= 475 nm).