LAUSR

cies in clinical findings. In addition, the spectroscopic methods possess poor selectivity, especially in a complex matrix such as serum or plasma. In a number of research works, the mixture of derivatization samples was separated using a liquid chromatography system and detected by an ultraviolet or fluorescence detector. The use of a separation system resolves some of the validation problems associated with the selectivity of spectroscopic methods; however, these methods still have low reproducibility and repeatability. The reasons for this poor validation of data originate from the high chemical reactivity of MDA, the strong acidic conditions and high temperature of the derivatization solutions, cross-reactivity of MDA with other biochemicals in the biological samples, and the low stability of standard solutions of MDA and derivatization reagents, which were comprehensively discussed in a recent publication. We strongly recommend that researchers in the field should test the validity of the analytical techniques used in their determination before reporting the data. Full details of validation procedures for analytical methods can be found in the literature. The validity and reliability of biochemical data should be double-checked before any meta-analysis. Finally, MDA should not be considered as a specific indicator of oxidative stress, as there is some doubts about its reliability.