Thioredoxin Reductase Colorimetric Assay Kit

Thioredoxin reductase (TrxR) is a ubiquitous key enzyme involved in critical cellular processes, including proliferation, p53 regulation, and oxidative stress defense. Mammalian TrxR not only reduces thioredoxin but also acts on diverse non-disulfide substrates—such as selenite, lipoic acid, lipid hydroperoxides, and hydrogen peroxide—playing a central role in redox homeostasis. TrxR activity measurement is therefore essential for studying cellular physiology, oxidative damage, and disease mechanisms.

Thioredoxin Reductase Colorimetric Assay Kit provides a rapid method for quantifying TrxR activity. TrxR can use NADPH as a coenzyme to catalyze the reduction of the substrate DTNB to generate yellow TNB, which absorbs maximally at 412 nm. Since other enzymes (e.g., glutathione reductase) may reduce DTNB in complex samples, the kit provides a TrxR-specific inhibitor. Specific TrxR activity is determined by subtracting the non-TrxR-mediated reduction (with inhibitor) from the total DTNB reduction (without inhibitor). This design ensures high specificity, effectively eliminates background interference, and provides a reliable method for TrxR functional studies.

Figure 1. Typical standard curve and assay data. (A) Thioredoxin reductase Kinetic Data, (B) The reference TNB standard curve.