Effect of blood sample storage period on d-ROMs and BAP test data.

The Diacron-reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) tests can easily and rapidly measure the state of oxidative stress in the blood; they have been used to determine the relationship between oxidative stress and various diseases. However, the extent to which the blood storage period affects the analyzed data remains unclear. In clinical practice, the storage conditions for samples after blood collection vary. Therefore, the influence of blood storage conditions, particularly the reversible redox state, on biochemical tests has been thoroughly investigated. The storage conditions of the sample may affect its state; however, its effect on oxidative stress has not been investigated yet. In this study, considering that the time from blood collection to blood cell separation differs depending on the clinical setting, we analyzed the effect of storage period on the redox analysis data of blood samples stored for a certain period in a 4 °C refrigerator without centrifugation. Heparinized plasma samples from three healthy adult men in their 30s were subjected to the d-ROMs and BAP tests. The analysis was performed at the following 12 time points: immediately after blood collection; 1, 3, 6, 12, and 24 h later; and 2, 3, 4, 5, 6, and 7 days later. The d-ROMs and BAP values varied and were unstable after 1 h of blood collection. These findings suggest that centrifugation should be performed within 1 h after blood collection, at the latest. In a clinical setting, data should be interpreted with caution if centrifugation is performed more than 1 h after blood collection, even if heparin is added and the samples are stored at 4 °C.