First and second dimension migration formulas. Master and vRLGS images for the human genome with the enzyme combination NotI-EcoRV-HinfI zoomed in on region 2D of the master profile. Spots labeled 1–7 are known sequences and are labeled on both the master and virtual profiles, with their overlap shown in the upper panels. The virtual spot labels are grey and outlined in red. A) – D) show the same window of the gels using the indicated migration formulas for the first and second dimensions (see materials and methods for formulas).