TMB显色液（ELISA，HRP显色用）

12 months from date of receipt / reconstitution, 2 to 8°C as supplied.

TMB (3,3',5,5'-tetramethylbenzidine) is a chromogenic substrate used for the detection of horseradish peroxidase (HRP) activity in enzyme-linked immunosorbent assays (ELISA), immunohistochemistry (IHC), and Western blotting. With a chemical formula of C₁₆H₂₀N₂ and a molecular weight of 240.34 g/mol, TMB is oxidized by HRP in the presence of hydrogen peroxide to produce a blue-colored product with maximum absorbance at 652 nm, which can be converted to a yellow product with absorbance at 450 nm upon the addition of an acidic stopping solution. The substrate solution should be protected from light and stored at 2–8°C, and contact with metal ions or strong oxidizing agents should be avoided to prevent spontaneous color development. In summary, TMB is a reliable and standard chromogenic substrate for HRP-based detection systems, playing an essential role in clinical diagnostics and life science research.