Whats with recombinational cloning (pDNR-Dual, pDONR201, pDONR221, etc. vectors)?
A. Most clones generated at HIP and shared with the repository are based on successful recombinational cloning methodologies such as the Clontech Creator system (LoxP sites) or the Invitrogen Gateway system (att sties). You can learn more about these approaches at vendors’ websites and at the HIP website http://www.hip.harvard.edu (look for information about FLEXGene clones). These flexible systems allow a single sequence-verified ORF (“master” or “donor” clone) to be used to create expression constructs for a variety of different techniques via recombination (few steps) rather than restriction enzyme cloning and ligation (several steps). In general, we keep the master clones in our collection because they give the most flexibility to the largest set of users. But in some cases, we also have expression versions.
