Fig. 7. Top panel: “Adaptive” PCR results for N2 reactions conducted in nasopharyngeal and 35 mM NaCl backgrounds with paired water controls (N = 6, duplicates). Nasopharyngeal trials (solid orange) display no change from control (dashed orange). 35 mM NaCl trials (solid blue) similarly show no difference from water background control (dashed blue). Bottom panel: identical samples conducted instead in traditional PCR, according to the CDC SARS-CoV-2 EUA (N = 3, duplicates). In contrast with the adaptive PCR results, all conducted in the nasopharyngeal (solid orange) and NaCl (solid blue) backgrounds failed, displaying false negative results. In comparison, the paired controls (dashed lines) all displayed similar performance to l-DNA controlled PCR.