Comparison of viewers for optical mapping data aligned to a region on chromosome 6 in GRCh37 featuring a sequence gap. (A) Optical consensus maps of cell line GM18994 (SwaI digest)  in gEVAL . The yellow track shows the aligned optical map fragments. Red inserts show fragments present in the optical map but absent from the reference. The virtual digest of the reference sequence is added in purple for comparison. (B) Gnomspace viewer  showing the same region and optical mapping data. Unaligned fragments are depicted in red. (C) OpGen’s Mapsolver alignment of an optical consensus map of cell line NA12878 (SpeI digest) to the same region. The upper track shows the virtual reference digest with the sequence gap indicated. The lower track shows the optical map including the currently missing fragments.