PCR-Based Screening for Bacterial Artificial Chromosome Libraries

The bacterial artificial chromosome (BAC) (1 ) is now the most widely utilized vector system to construct large-insert genomic libraries for genome analysis. It has the following advantages over another vector system, the yeast artificial chromosome (YAC) (2 ): ease of DNA purification, a lower rate of chimerism, stable maintenance of inserts, and compatibility with templates for sequence determination. Regarding screening, it is very important that BAC-DNAs can be separated from genomic DNA of the host, as the host DNA often competes with BAC-DNAs for the amplification of expected PCR fragments.