Related Experiment Videos
A fluorimetric assay for hydrogen peroxide, suitable for NAD(P)H-dependent superoxide generating redox systems
R Rapoport1, I Hanukoglu, D Sklan
1Department of Hormone Research, Weizmann Institute of Science, Rehovot, Israel.
Analytical Biochemistry
|May 1, 1994
Summary
This study introduces a sensitive fluorimetric assay to quantify hydrogen peroxide (H2O2) and superoxide production during electron transfer. The method uses formaldehyde conversion and offers a reliable tool for studying reactive oxygen species generation.
Area of Science:
- Biochemistry
- Analytical Chemistry
- Biophysics
Background:
- Reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and superoxide, play critical roles in cellular signaling and disease.
- Quantifying ROS production rates is essential for understanding biological processes and oxidative stress.
Purpose of the Study:
- To develop a simple, sensitive, and reproducible fluorimetric method for the quantitative assay of hydrogen peroxide and superoxide production.
- To enable simultaneous measurement of ROS production and NAD(P)H oxidation in enzymatic systems.
Main Methods:
- A novel assay involving superoxide dismutase, catalase, and methanol to stoichiometrically produce formaldehyde from H2O2.
- Formaldehyde is converted to diacetyldihydrolutidine (DDL) using Nash reagent, with fluorescence measured at specific wavelengths (Ex 412 nm, Em 505 nm).
- Assay validation in a mitochondrial P450 system to determine electron flow to oxy-radical formation.
Main Results:
- The assay demonstrates high reproducibility (CV < 15%) for measuring micromolar amounts of H2O2.
- The fluorescence detection wavelengths are distinct from NAD(P)H, allowing simultaneous measurements.
- The method successfully quantified oxy-radical formation in a mitochondrial P450 system.
Conclusions:
- This fluorimetric assay provides a robust method for quantifying hydrogen peroxide and superoxide production rates.
- The assay is suitable for NAD(P)H-dependent systems and valuable for studying ROS generation in various biological contexts.