Measurement of cytoplasmic Ca²⁺ concentration in Saccharomyces cerevisiae induced by air cold plasma

In this study, a novel approach to measure the absolute cytoplasmic Ca²⁺ concentration (Ca²⁺cyt) using the Ca²⁺ indicator fluo-3 AM was established. The parameters associated with the probe fluo-3 AM were optimized to accurately determine fluorescence intensity from the Ca²⁺-bound probe. Using three optimized parameters (final concentration of 6 mM probe, incubation time of 135 min, loading probe before plasma treatment), the maximum fluorescence intensity (F_max=527.8 a.u.) and the minimum fluorescence intensity (F_min=63.8 a.u.) were obtained in a saturated Ca²⁺ solution or a solution of lacking Ca²⁺. Correspondingly, the maximum
Ca²⁺cyt induced by cold plasma was 1232.5 nM. Therefore, the Ca²⁺ indicator fluo-3 AM was successfully applied to measure the absolute
Ca²⁺cyt in Saccharomyces cerevisiae stimulated by cold plasma at atmospheric air pressure.