BAC-by-BAC strategy

 Also known as hierarchical shotgun sequencing or a clone-by-clone shotgun strategy.

            Method for genome sequencing based on a two-step progression. First, a physical map of the target genome (or chromosome) is established using BAC clones (typically 100–150 kb) and a set of overlapping clones representing a minimal tiling path (MTP) is then ordered along the chromosomes of the target genome. The individually mapped clones of the MTP are then subjected to shotgun sequencing. DNA from each BAC clone is fragmented randomly into smaller pieces that are either cloned into a plasmid and sequenced with Sanger sequencing technologies or directly sequenced via NGS technologies. The sequences are then aligned so that identical sequences overlap and contiguous sequences (contigs) are assembled into a finished sequence.