CheKine™ Micro TPX Assay Kit: Your Buyer's Guide for the Cell's Frontline Defender Against ROS
The 30-Second Verdict
Thioredoxin peroxidase (TPX)—also called peroxiredoxin—is the cell's frontline defender against reactive oxygen species (ROS), mopping up hydrogen peroxide and lipid peroxides to protect DNA, proteins, and membranes[reference:95]. Its activity is tied to everything from cancer progression and neurodegeneration to plant stress tolerance and aging[reference:96]. Abbkine's CheKine™ Micro Thioredoxin Peroxidase (TPX) Assay Kit (KTB1660) is a no-fuss, budget-friendly solution that fixes the flaws of old-school kits, without sacrificing precision[reference:97]. Priced at 100+ for the same count[reference:98].
Pros
✅ Proprietary thioredoxin-coupled enzymatic cycling method — tracks NADPH consumption (340 nm) for direct TPX measurement[reference:99]
✅ Microvolume design — only 10–20 µL sample per reaction (50–70% less than traditional assays)[reference:100]
✅ Exceptional specificity — cross-reactivity with other antioxidant enzymes <2%[reference:101]
✅ High sensitivity — LOD of 0.01 mU/µL (10x better than DTNB-based kits)[reference:102]
✅ Colorimetric readout — works with any standard microplate reader at 510 nm[reference:103]
✅ Broad detection range — 0.1–10 U/L[reference:104]
✅ Broad sample compatibility — cell lysates, tissue homogenates (liver, brain, plant leaves), serum, microbial cultures[reference:105]
✅ Peroxidase blocker included — sodium azide silences glutathione peroxidase, cutting cross-reactivity[reference:106]
✅ Long shelf life — 18 months at -20°C (signal variation <6%)[reference:107]
Cons
❌ Requires -20°C storage, protected from light
❌ Not for clinical diagnosis (research use only)
❌ Requires a microplate reader capable of 340 nm or 510 nm absorbance
Who Should Buy This Kit?
Ideal for:
- Researchers studying oxidative stress in neurodegeneration (Alzheimer's, Parkinson's)
- Cancer biologists investigating ROS-driven tumor progression
- Plant scientists studying drought tolerance and stress responses
- Toxicologists assessing pollutant-induced oxidative damage
- Labs working with primary cells, rare biopsies, or small-animal models[reference:108]
- Labs on tight grants needing cost-effective solutions[reference:109]
Skip this if:
- You lack a microplate reader
- You need to measure total antioxidant capacity (use TAC assays instead)
How It Works: The Thioredoxin-Coupled System
Instead of DTNB (which has three glaring flaws: 50–100 mg tissue requirement, 30% cross-reactivity, 3+ hours to develop color), KTB1660 uses a proprietary thioredoxin-coupled enzymatic cycling method: TPX reduces H₂O₂ using thioredoxin (Trx), and the resulting oxidized Trx is recycled by thioredoxin reductase (TrxR) with NADPH[reference:110]. A colorimetric readout (λmax = 510 nm) tracks NADPH consumption, which correlates directly with TPX activity[reference:111].
Validated in Real-World Research
- Plant stress studies: 5 mg leaf tissue in 10 µL extraction buffer (with PVPP to bind phenolics), 20 µL supernatant loaded[reference:112]
- Human cell research: 10⁴ cells lysed in 15 µL buffer, skip ultracentrifugation[reference:113]
- Drought-stressed wheat: Handles phenolic interference that other kits struggle with[reference:114]
Critical Sample Handling Tips
- For cell lysates: Use ice-cold RIPA buffer (supplemented with 1 mM PMSF and 5 mM DTT) to preserve TPX activity—heat and harsh detergents denature this enzyme fast[reference:115]
- Homogenize at 4°C and centrifuge at 12,000 rpm for 15 minutes[reference:116]
- Incubate 30 minutes at 25°C, read absorbance[reference:117]
- For plant samples: PVPP in extraction buffer binds phenolics that interfere with the assay[reference:118]
The Bottom Line
For researchers who need to measure TPX activity in precious, limited samples—whether rare patient biopsies, stressed plant leaves, or small-animal models—KTB1660 delivers the specificity, sensitivity, and affordability that modern oxidative stress research demands.
👉 Quantify TPX activity with confidence. View Product
