Illustration of molecules and an ELISA Plate

Soluble HRP Substrates

Soluble Horseradish Peroxidase (HRP) Substrates

In a soluble chromogenic HRP assay setup, like an ELISA, the preferred substrate is TMB (3, 3', 5, 5'-tetramethylbenzidine). When developing immunoassays, choosing the right TMB is a vital step for optimizing the assay. Kementec offers a range of TMBs with different kinetics and sensitivities, enabling assay developers to choose the right TMB for their assay.

All the TMBs are ECO-TEK, making them REACH, Annex XVII0 compliant and easy to transport with less restrictions. ECO-TEK includes:

  • Free of BSA
  • Free of NMP or other harmful organic solvents – 100% aqueous
  • Free of toxic preservatives and hazardous stop solutions

The TMBS are characterized by outstanding sensitivity, stability and stop-stability, and very high lot-to-lot consistency. Offering a shelf life up to 4 years of the ready-to-use substrates enables Kementec products to meet all the requirements of assay manufacturers.


Several of the TMBs are suitable for use in electrochemical assays that utilize sensor measurements. 

TMB substrates are also available as unique color-coded products for traceable pipetting. The pink indicator makes manual pipetting traceable, while in automatic analyzers it offers a convenient tracking system for reagent supply. The color disappears after adding the recommended stop solution and does not interfere with the assay.

Corresponding diluents are available for TMB substrates in order to achieve a specific activity level.