Methodological Approaches to the Assessment of the Content of Reactive Oxygen Species and Lipid Peroxidation Products

This article explores the methodological approaches to analyzing free radical processes in the body, particularly in relation to lipid peroxidation products (PLP). The levels of reactive oxygen species (ROS) and PLP were shown to vary depending on the time and conditions of biomaterial storage, which may affect the reliability of the results. It was revealed that the optimal storage conditions include freezing ( t = ‒20 °C) for the determination of ROS and diene conjugates (DC) and deep cooling ( t = ‒80 °C) for malondialdehyde (MDA). For the determination of Schiff bases, the temperature of biomaterial storage was found to be non-essential. The analysis period after receiving the biomaterial was defined as follows: up to 2 h for Schiff bases, up to 24 h for ROS, up to 36 h for MDA, and up to 48 h for DC. The obtained results can be useful for further scientific research and in clinical diagnostic laboratories that perform prooxidant-antioxidant balance tests.