Abstract: Disclosed are consensus optical contig maps of an entire genome of an organism and methods of using the maps to verify, validate, refute and/or access the accuracy of a known nucleic acid sequence or full genomic sequence. The maps are constructed using optical methods wherein DNA is elongated and fixed along their length onto a solid planar surface so that the DNA molecules are individually analyzable and accessible for enzymatic reactions. The DNA molecules are then reacted with a restriction enzyme to yield cleaved fragments of discernable length fixed to the surface. The lengths of the fragments are then determined, using optical methods. From the lengths determined, an optical contig map is assembled and can be compared to a corresponding known sequence, for example, a genomic sequence.