ELISA Stop Solution is a ready-to-use solution intended for use as a stop solution in ELISA applications that use horseradish peroxidase and TMB substrate solution.
In commercial ELISA kit, the most commonly used stop solution is 0.5~2M sulfuric acid, which is an acidic solution prepared from 98% sulfuric acid. Here is the recipe for this solution.
Caution: sulfuric acid is dangerous, please handle with care. The dilution or dissolve with water may produce heat, wear proper lab protections such as goggle, gloves, mask,etc to protech yourself.
Caution: Sulfuric acid (95%-98%) is a restricted chemical, please make sure it is obtainable in your country. If you don't have the permit, please contact local authorities for help.
For 1000mL stop solution at 2M,
(1) Take sulfuric acid (95%-98%, density 1.84g/mL) 106ml and dissolve with distilled water or deionized water.
(2) Further dilute to 1000mL.
(3) The final concentration is around 2M.
Since stop solution is only to stop the biochemical reaction, 0.5M - 2.0M sulfuric acid all can work. Don't worry if your stop solution is not so accurately prepared.
After stop the reaction, the whole ELISA plate will turn to yellow from blue, then read the ELISA plate with an ELISA reader at 450nm.
Other frequently asked questions about stop solution.
1. How long can this stop solution be valid?
Since the solution is pretty acidic, it can be valid at least for 1 year, even when it is stored at room temperature.
2. Can I replace the sulfuric acid with other acidic solution?
Yes, other acidic solution such as HCl, etc, can work.
3. What if the sulfuric acid stolution contact my skin?
Caution, the sulfuric acid solution is very dangerous. If the stop solution contact your skin, try to wash with cold water for at least 20min until you can not feel any burning. See a physician immediately.
4. Can I use this stop solution in other commercial ELISA kit?
Yes, as long as they are from Ringbio. If not, please confirm that the substrate is TMB, then you can use this.
