Search
Storage & Stability
How should I store TMB substrate? Store at 2-8 C, protect from light, and bring to room temperature before use.
How long is the shelf life? Up to 4 years by formulation (varies by product).
What about freeze-thaw? Durastab offers freeze-thaw resistant variants (suffix -F); after repeated freeze-thaw at -20 C they retain >95% activity. Standard substrates should not be frozen.
Is it stable when opened? Durastab TMB has shown open-vial stability >1 year at 2-8 C under repeated-use testing.
Wavelength & Reading
What wavelength do I read? 450 nm after stopping, or 650 nm if reading without stopping (kinetic mode).
Do I need a stop solution? Not required, but it fixes the endpoint and stabilizes the yellow chromophore for convenient reading.
Sensitivity & Kinetics
Which substrate is fastest / most sensitive? High Sensitive is the fastest-ramping, highest-sensitivity option.
Which has the widest range? Slow Plus has the widest dynamic range; Board Range also provides a broad range.
How to Use TMB Substrate (Protocol)
1. Equilibrate the substrate to room temperature and mix by gentle inversion.
2. Add a working volume, typically 100 uL/well, after the HRP-conjugate step and washing.
3. Incubate at room temperature (or follow your protocol) for 10-30 min, protected from direct light.
4. Stop with 100 uL stop solution to fix the endpoint (optional if reading kinetically).
5.Read at 450 nm within 30 min of stopping (or 650 nm if reading without stopping).
Incubation & Timing
How long should TMB be incubated? It depends on the formulation. High Sensitive develops in roughly 10-15 min, Board Range across ~10-30 min, and Slow Plus over ~15-30 min.
What temperature should I use? Development is faster at 37 C and slower at room temperature; choose a temperature that gives you a controllable timing window and stay consistent across plates.
Should I protect from light? Yes - keep substrate and developing wells away from strong light to minimize background.
Troubleshooting
Weak signal / no color? Check HRP conjugate activity, TMB freshness, temperature and development time; verify the plate reader wavelength (450/650 nm).
High background? Confirm blocking and wash steps; avoid over-development; check substrate for contamination or light exposure.
Color appears but OD stays flat? You may be reading at the wrong wavelength or hitting saturation - read earlier or use a less sensitive formulation.
Ordering & Customization
Can I order large volumes? Yes - available up to bulk and large single batches (up to 1950 L).
Do you offer custom formulations? Durastab can tailor TMB formulation to specific development needs; contact us for custom activity or additional product codes.
Are samples available? Contact our team for sample or quote options.
What sizes are available? 100 mL, 1 L, 5 L and 10 L, with bulk supply for larger volumes.
What documents do you provide? A Certificate of Analysis (CoA), product data sheet and material safety documents are available on request.
