EGFR-L858R (Exon 21) L858R CTG > CGG a g b h L858 CTG c i L858R CTG > CGG d j e k f l Supplemental Data Figure 3. Quantitative detection of EGFR exon 21 L858R kinase domain mutation in resected NSCLC tumor genomic DNA using the nanofluidic digital array.(a-k) Examples of digital-PCR array detection of L858R mutation in genomic DNA from 10 patients (panels a-e, and g-k) are shown here, with 5,000 copies of DNA molecules each panel. NSCLC-15 [DID-Panel (a)] and NSCLC-20 [DID-Panel (k)] had 103 and 463 mutated L858R alleles detected respectively. The mutated codon CTG>CGG (L858R) from NSCLC-15 was barely detectable in DNA sequencing. Other samples that harbored rare L858R alleles of 0.02-0.04% (NSCLC-3, -13, -14 and -19) did not have the rare mutant alleles detected by direct DNA sequencing (see also Supplemental Data Figure 4).