Hybridization-Based Selection of BAC Clones

Studying large genomic regions at the molecular level requires access to the DNA representing such sites. The availability of large and stable clones derived from target genomic regions is essential for detailed analysis such as sequencing. Since its introduction in 1992, the bacterial artificial chromosome (BAC) library system has been widely employed as a standard cloning system for mapping and sequencing the genomes of human and model organisms (1 ), as well as in a variety of other research areas where large DNA insert-containing clones are needed (2 –24 ). With the end of the Human Genome Project drawing near (25 ), the genome-sequencing community is now directing its efforts at sequencing commercially important organisms. BAC library construction and high-throughput screening has become an indispensable tool for the isolation of large chromosomal DNA fragments necessary for such projects.