Product Description

1-Methoxy PES is an electron mediator which has higher stability of solutions than 1-Methoxy PMS(M003). The stability in neutral to alkali conditions has been extremely improved with 1-Methoxy PES. 1-Methoxy PES is a stable small-molecular compound and it has an equal or higher thermal stability than diaphorase. The 1-Methoxy PES solution can be stored long term.

Characteristics of Each Electron Mediator

Stable in Wide Range of pH – Comparison with 1-Methox PMS

Methods:The residual activity of electron mediator was determined by colorimetric measurement after mixing WST-8 and NADH to the electron mediator solution that was stored for 30 days at 30 ^oC.

Result:The stability of 1-Methoxy PMS solution dropped drastically at pH6 and above, on the other hand, 1-Methoxy PES solution was stable until pH8.

Solution Stability Compared to Diaphorase

Methods:Working solution:1mmol/l WST-850 mmol/l HEPES buffer (pH7.0)1% Triton X-1001-Methoxy PES (final concentration of 2 umol/l) or diaphorase (final concentration of 0.05 U/ml) was mixed with the working solution. 100 ul of 200 umol/l NADH (50 mmol/l HEPES buffer pH7.0) was added to 100 ul of each electron mediator solution. After 20 minutes at 37 ^oC, an absorbance of WST formazan was read (450nm). The freshly prepared solution and the solution stored for 45 days at 5^oC were utilized for residual activity comparison.

Result:There was 20% drop in the residual activity of diaphorase after 45 days of storage, on the other hand, 1-Methoxy PES showed similar residual activity as a freshly prepared solution.