– DPPP is a probe that reacts stoichiometrically with hydroperoxides to yield the fluorescent molecule diphenyl-1-pyrenylphosphine oxide (DPPP-O). Plasma levels of lipid hydroperoxides of phosphatidylcholine, phosphatidylethanolamine, triglycerides, and cholesteryl esters have been measured by HPLC with a post column detection system using DPPP. DPPP has also been used as a fluorescent probe for the detection of low density lipoprotein and cellular oxidation. Fluorescence of DPPP-O can be monitor using excitation and emission wavelengths of 351 nm and 380 nm, respectively.