NAS using graph pseudoalignment in GNASTy. (1A) The start of a DNA fragment passes through a nanopore, disrupting the movement of ions and causing a change in current determined by the base passing through the pore. (1B) This current change is used to basecall the read. (2) The read is k-merized, depending on the k-mer size used to build the DBG. (3A) The k-mers are matched to those in the graph via pseudoalignment, analogous to traversing a hypothetical path (dotted green line). (3B) The number of matches (green) and mismatches (red) are used to calculate the proportional number of k-mer matches between the read and the hypothetical path in the graph. (4A) If the read surpasses the predefined identity threshold, the remainder of the DNA is sequenced. (4B) If not, the voltage is reversed across the membrane, pushing the read in the reverse direction and freeing the pore to sequence a new DNA fragment.
