Dihydroethidium (PD-MY 003) is a peroxide indicator with blue fluorescence in the cytoplasm (λex=518 nm, λem=616 nm), which disappears when oxidized and is cell permeable.

METHODS: Detection of cellular peroxides by Dihydroethidium:
1. Prepare a 5-10 mM stock solution of Dihydroethidium dye in DMSO, protect from light, and store in portions at -20℃.
Dilute the stock solution with physiological buffers (e.g., PBS, HBSS, HEPES) to obtain a working solution of 5-20 µM Dihydroethidium dye. The optimal working concentration must be determined empirically.
3. Add the Dye Working Solution to the cells at a 1:1 ratio (100 µL of Dye Working Solution to 100 µL of Cell Suspension) and incubate for 5-60 minutes at room temperature or 37℃.
4. Wash with PBS and then perform fluorescence microscopy or flow cytometry. Dihydroethidium itself is blue fluorescent with a maximum excitation wavelength of 370 nm and a maximum emission wavelength of 420 nm, and after dehydrogenation, it binds to RNA or DNA to produce red fluorescence with a maximum excitation wavelength of 300 nm and a maximum emission wavelength of 610 nm, and 518 nm can be used as the excitation wavelength in practice.