## 3 Results
### Chemical Comparison and Mock Treatment Are Inaccurate Markers of Cellular Responses
We repeated the measurements in DI water to show that our measurements were consistent with those reported in the literature for both devices:  
1. Concentrations of H\({}_{2}\)O\({}_{2}\) in DI water (6.49 and 17.49 \(\upmu\)M after 2 and 4 min, respectively) and NO\({}_{2}\)\({}^{-}\) (1.15 and 2.01 \(\upmu\)M, respectively) for the COST-Jet [21; 43]. 2. For the nspDBD [14], the H\({}_{2}\)O\({}_{2}\) concentration in DI water increased from 109.6 \(\upmu\)M to 150.1 \(\upmu\)M and NO\({}_{2}\)\({}^{-}\) concentrations from 3.9 \(\upmu\)M to 9.01 \(\upmu\)M when the frequency was increased from 45 to 75 Hz. Figure 5: Concentrations of H\({}_{2}\)O\({}_{2}\) (**Left**) and NO\({}_{2}\)\({}^{-}\) (**Right**) in DI water (solid line) or RPMI (Roswell Park Memorial Institute) supplemented with 10% fetal bovine serum (FBS) and 1% penicillin/streptomycin (P/S) (dashed line) post plasma treatment. The gas control and untreated H\({}_{2}\)O\({}_{2}\) measurement indicate the medium itself is detected by the peroxide kit used. These experiments were repeated once, and the data plotted represent the mean and standard deviation. The organic and oxidizable components of the culture medium, as well as the higher pH, should buffer the oxidative capacity of the plasma-generated RONS and reduce their concentrations. The chemical pathways for H\({}_{2}\)O\({}_{2}\) formation from plasma treatment are described through the following mechanisms [44]:  
\[\mathrm{OH+OH\to H_{2}O_{2},} \tag{1}\]  
\[\mathrm{HO_{2}+H_{2}O+O_{2}^{-}\to O_{2}+OH^{-}+H_{2}O_{2},} \tag{2}\]  
\[\mathrm{2\ HO_{2}\to O_{2}+H_{2}O_{2},} \tag{3}\]  
while a significant portion of H\({}_{2}\)O\({}_{2}\) produced during plasma treatment is in the gas phase and is subsequently solvated, there is also the possibility of forming H\({}_{2}\)O\({}_{2}\) in the liquid phase [29]. The pathway depicted by reaction (1) forms H\({}_{2}\)O\({}_{2}\) at the liquid interface from plasma-generated OH. The latter two reactions (2,3) mainly occur in the bulk liquid as secondary chemistry. H\({}_{2}\)O\({}_{2}\), OH, and O\({}_{2}\)\({}^{-}\) will react readily with the medium components, which should significantly reduce the concentration of H\({}_{2}\)O\({}_{2}\) formed by reactions (1) and (2). However, the higher concentrations observed in the medium suggest the formation of organic peroxides from both plasma sources. This has been previously hypothesized by [PERSON] et al. [45], based on the reaction between solvated ozone (O\({}_{3}\)) and organic compounds [46]. Experimentally, it was shown by [PERSON] et al. that O\({}_{3}\) and O produced using the COST-Jet (0.6% O\({}_{2}\) admixture) increased the H\({}_{2}\)O\({}_{2}\) concentration in DI water if phenol was present [47]. For our investigation, the O and O\({}_{3}\) produced by the COST-Jet [47; 48] and RONS produced from the nspDBD at ambient conditions [49] could solvate and produce higher concentrations of H\({}_{2}\)O\({}_{2}\) in the medium in comparison with DI water. The considerably higher production of H\({}_{2}\)O\({}_{2}\) and NO\({}_{2}\)\({}^{-}\) of nspDBD treatment showed the stronger oxidative environment of the nspDBD in comparison to the COST-Jet. The H\({}_{2}\)O\({}_{2}\) concentrations from these treatments alone should adversely impact viability [41]. However, the biological responses of Jurkat cells to both treatments were comparable under these exposure conditions. These cells, which were sensitive to oxidation, exhibited similar responses when exposed to two different plasma chemistries of differing oxidative magnitude. We tested the cellular response to H\({}_{2}\)O\({}_{2}\) and NO\({}_{2}\)\({}^{-}\), both alone and in combination, as a mock treatment to understand if the long-lived species had the oxidative impact to affect the cells. In lieu of plasma treatment, these cells were exposed to exogenously added concentrations of H\({}_{2}\)O\({}_{2}\) and NO\({}_{2}\)\({}^{-}\) (Table 2), as measured in DI water.