Retrofitting BACs With a Selectable Marker for Transfection

Many functional studies require the transfection of bacterial artificial chromosome (BAC) clones into mammalian cells. Because most BAC vectors do not have a mammalian selection marker or do not have one suitable for all cell types, it is usually necessary to modify BAC clones to include a selection marker, a “retrofitting” process. Different BAC retrofitting strategies have been developed over the last 5 yr and are classified in the reference section (1 –11 ).