Thanks to its extensive unsaturation, paranaric acid is quite susceptible to oxidation. It is this property that is utilized in measuring lipid peroxidation. Because a 325 nm UV excitation source is required, the use of paranaric acid is restricted to spectrofluorometry and flow cytometers with helium-cadmium lasers.
Note in the above data, the left figure is reproduced from the reference listed, however the data on the right is simply a cartoon representation of the the mean kinetic change that would be observed from the data on the left.
Data taken from Hedley, et al, Cytometry, 13: 686-692, 1992
