NGS clonal sequencing allows direct detection of independent disease clones. (A) Two C to T substitutions in TET2 exon 11 are depicted by the dominant red bars and are found in approximately 17% of sequence reads (17% variation [left axis] from the reference sequence [x-axis]). The sequence coverage (number of reads) across the region is shown on the right axis and is traced by the blue line. Experimental noise is shown underneath the dotted line with reads for bases A (green bars), C (blue bars), G (black bars), T (red bars), and base deletions (gray bars) at less than 4% of reads. (B) A selection of individual sequence reads lined up against each other is shown and demonstrates that the 2 mutations are found in separate molecules being sequenced and thus belong to independent clones or alternate alleles.