Figure 1. The multi-disciplinary process of optical mapping.

(A) High molecular weight DNA is extracted and chemically labeled at sequence-specific sites to generate a genetic barcode. Additional labeling of various information layers such as epigenetic marks can follow, and finally the DNA backbone is stained with an intercalating dye. (B) Using an electrical field, DNA molecules are unraveled from their entangled state and forced into nanochannels for linearization. Within the nanochannels, the labeled molecules are imaged in multiple colors (image obtained on BioNano Genomics Saphyr system). The molecules and their fluorescent marks are then detected and localized, and image analysis is performed for their digitization. (C) The digitized barcodes are then used to infer the molecules' genomic origin, either by their alignment to a known reference genome, or their assembly de novo. (D) The resulting genomic (and epigenetic) information obtained is used for biological analysis based on structural variants, copy number aberrations, genome phasing and population analyses.