3,3'5,5'-Tetramethylbenzidine (TMB) has been shown to be a safe-sensitive substrate for the assay of horseradish peroxidase (HRP). Initially, in the presence of HRP and hydrogen peroxide, a one-electron oxidation product is formed. This compound, a cation free radical, is blue in color with an adsorption maximum at 653 nm. Further reaction with HRP/H, or acidification of the radical with acid yields the diimine terminal oxidation product adsorbing light at 450 nm. The extinction coefficient of the radical (E653 nm = 3.9 x 10 mo⁻1 cm⁻) and diimine (E450 nm = 5.9 x 10 mol⁻ cm⁻) provide a remarkably sensitive system for the assay of HRP and HRP labeled probes. TMBUS, available from Biovision Inc., is a single component reagent stable at room temperature and not sensitive to normal laboratory light. It is optimized with respect to TMB and hydrogen peroxide concentrations and yields a linear response with the concentrations of HRP usually employed in immunologic assays.

Additional Information

Synonyms	3,3',5,5'-Tetramethylbenzidine; TMBUS
Product #	T-2464
CAS #	54827-17-7
Chemical Name	3,3',5,5'-Tetramethylbenzidine; TMBUS
Formula	C16H20N2
MW	240.35
Appearance	Liquid
Storage Temp	+4°C
Use	TMB is a chromogenic substrate used in staining procedures in immunohistochemistry as well as being a visualising reagent used in enzyme-linked immunosorbent assays

Additional Information

MDL Number	MFCD00007748
ChemACX	X1009100-2
InChI	InChI=1S/C16H20N2/c1-9-5-13(6-10(2)15(9)17)14-7-11(3)16(18)12(4)8-14/h5-8H,17-18H2,1-4H3
SMILES	Cc1cc(cc(c1N)C)c2cc(c(c(c2)C)N)C