Sensitivity of rearrangement detection at the MYC locus with Vysis and Dako FISH probes. The horizontal axis represents genomic space on chromosome 8 (chr8). Translocations are represented by vertical ticks along the axis, with symbols describing the rearrangement partner labeled above. White crosses denote cases that were MYC break-apart positive by Dako only (ie, Vysis failed). The shaded blue region represents the space where rearrangements can be detected by both assays, and the shaded purple region shows where only Vysis can detect rearrangements. The approximate location of FISH binding probes is shown on the middle track. Representative FISH images show observed patterns: cases in the blue region produce a fusion signal and a break-apart signal in both assays (left); cases with breakpoints that lie within the Dako red probe binding region produce 2 fusion signals and a small additional red signal, as indicated by the white arrow (center); and cases in the purple region produce a break-apart signal with Vysis and 2 fusion signals with Dako (right). Breakpoints corresponding to the FISH images are indicated by black arrows under the chromosome track.