Fig 6. Comparison of CNAs in the same set of biomarkers in matched frozen and FFPE tissue specimens measured by our multiplexed ddPCR method.

Mean normalized R_i/b values were determined for 15 biomarkers in DNA extracted either frozen or FFPE tissue biopsies of SCC in Area 1 ($■$) or the dysplasia in Area 2 (○). In general good agreement of normalized R_i/b values is observed between the matched samples when the fragmentation correction is applied (A), while a much poorer agreement is observed when the fragmentation correction is not applied (B). Error bars represent a 95% confidence interval.