Fig. 2

dPCR analysis of KRAS status in cell lines, culture supernatants, tumor tissue xenotransplants and mouse plasma. Input DNAs (from FFPE specimens, culture supernatants and ctDNAs) were subjected to chip-based dPCR using a duplex TaqMan assay that discriminates between WT (red) and mutated KRAS (blue) amplimers at codons 12 and 13, as indicated. Double-positives (microwells containing both WT and mutated KRAS) are shown in green. Microwells in which no PCR amplification takes place are represented by yellow dots (lower left). Variant Allele frequency was calculated by dividing the number of mutated DNA by the total number (mutant +WT) of amplified alleles. Copies per mL are noted and color-coded in supernatants and plasma samples. A whole chip view is depicted in the insets as a quality control