Mapping of the ampGR on chromosome 21 and identification of the AFS sequences. (a) Ideogram of chromosome 21 and corresponding data of the Affymetrix whole genome array. The amplified genomic region (ampGR) of chromosome 21 is highlighted in green. Data is presented as Log2-ratios of internal normalized signal intesities. (b) Data of the high resolution tiling array (NimbleGen). The relative copy number for each printed oligonucleotide are presented as fluorescent intensities of the Cy5 labelled test-DNA (cell lines) normalized to the Cy3 labelled reference-DNA (healthy human female) (Log2-ratio). The mean signal intensity value of the continuous genomic region was calculated by the SignalMap-Software and is indicated by the red line. The ampGR is highlighted in green. (c) Model of the architecture of the AML1/RUNX1 amplicon. AmpGR are subsequently joined together in head-to-head and tail-to-tail orientation, resulting in tumor cell specific AFS. Primer for PCR are displayed as open or filled squares. (d) Chromatogram of the sequenced junction site of the head-to-head AFS-PCR-amplimer. (e) Chromatograms of the sequenced junction sites of the tail-to-tail AFS-PCR-amplimer.