After the sample passes quality inspection, the genomic DNA is randomly fragmented. Then, magnetic beads are used to enrich and purify large DNA fragments, which are subsequently gel-extracted and subjected to damage repair. Following purification, the ends of the DNA fragments are repaired and an 'A' tail is added. The SQK-LSK109 ligation kit is used to perform the adapter ligation reaction. Finally, the constructed DNA library is quantitatively assessed. Once the library preparation is complete, a specific concentration and volume of the DNA library are loaded into the Flow cell, which is then transferred to the Oxford Nanopore PromethION sequencer for real-time single-molecule sequencing.