Courtesy of Invitrogen
Key to Invitrogen's Gateway technology is the "entry clone," which contains a fragment of interest in a recombinase-ready plasmid. Researchers can quickly and efficiently move between expression systems without subcloning by swapping the insert from vector to vector.
Cloning DNA fragments using restriction enzymes is like flying from Seattle to New York via Phoenix. You arrive at your destination, but it takes longer than necessary to get there. Restriction sites, like airline hubs, aren't always where you need them, and sometimes they aren't there at all.
Recombinase-based methods allow scientists to move pieces of DNA from plasmid to plasmid without restriction enzymes, simplifying and expediting the cloning process. It also prevents the aggravation that comes from realizing your insert contains inconveniently placed restriction sites, or just as bad, none at all.
Such systems are useful for shuttling inserts from vector to vector – for instance, to tag ...
