Ascorbic Acid Sensing Reveals Its Different Stability in Biological Media

Investigation on the physiological and pathological significance of ascorbic acid (AA) has drawn extensive interest, and as a consequence, information on the AA stability in various biological media becomes essential to ensure research reliability. In this study, we develop sensing methods to systematically investigate AA stability across diverse biological media and reveal significant differences. AA exhibits poor stability in commonly used biological solutions, including phosphate-buffered saline (PBS) and Hank's balanced salt solution (HBSS), with the concentration decreasing by approximately 42.8% and 45.4% over 72 h. Degradation significantly accelerates in cell culture media, including Dulbecco's Modified Eagle's Medium (DMEM) and Roswell Park Memorial Institute (RPMI) 1640 medium, showing 62.0% and 90.5% losses within 24 h, respectively. In artificial cerebrospinal fluid (aCSF) generally used as in vivo perfusion fluid, AA concentration decreases by 91.1% over 72 h, while in brain slice incubation solution (BSIS), a 72.6% decrease is observed within 4 h. In contrast, in physiological saline (0.9% saline), AA shows minimal degradation, retaining 98.5% AA over 72 h. This study profiles the AA stability across diverse biological media, providing guidance for AA usage in biological research.