TMB (hydrochloride hydrate)

Cayman Chemical Item Number 70450

(CAS 207738-08-7)

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TMB is an aromatic amine that undergoes oxidation by the higher oxidation states of heme peroxidases (compounds I and II) thereby serving as a reducing co-substrate. One electron oxidation of TMB results in a radical cation that forms a charge-transfer complex with the unoxidized compound. This charge transfer complex absorbs at 652 nm (ε = 39,000).1 The completely oxidized form (diimine) absorbs at 450 nm (ε = 59,000) and is formed by two sequential one-electron oxidations of TMB.1,2 Thus the stoichiometry of oxidation is 0.5 mole charge transfer complex (λmax = 652 nm) or 1 mole of diimine (λmax = 450 nm) formed (or TMB oxidized) per mole of hydroperoxide reduced by the peroxidase.

1. Josephy, P.D., Eling, T., and Mason, R.P. The horseradish peroxidase-catalyzed oxidation of 3,5,3',5'-tetramethylbenzidine. Free radical and charge-transfer complex intermediates. J Biol Chem 257 3669-3675 (1982).

2. Marquez, L.A., and Dunford, H.B. Mechanism of the oxidation of 3,5,3',5'-tetramethylbenzidine by myeloperxidase determined by transient-and steady-state kinetics. Biochemistry 36 9349-9355 (1997).

Formal Name 3,​3',​5,​5'-​tetramethyl-​[1,​1'-​biphenyl]-​4,​4'-​diamine,​ dihydrochloride,​ dihydrate
CAS Number 207738-08-7
Molecular Formula C16H20N2 • 2HCl [2H2O]
Formula Weight 349.3
Formulation A crystalline solid
Purity ≥98%
λmax 295 nm
Stability 1 year
Storage -20°C
Shipping Room temperature in continental US; may vary elsewhere
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Size Price Quantity Subtotal
100 mg $29.00 $0.00
250 mg $43.00 $0.00
1 g $57.00 $0.00
5 g $214.00 $0.00
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Cart Total $0.00

Pricing updated 2015-07-31. Prices are subject to change without notice.

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