| Date: April 13, 1998 | PCR Based Cloning Kits Table The End Table (PDF Format) |
PCR-based cloning kits have come along to fill this niche. Novel approaches to cloning PCR fragments have been devised, and as detailed in the company profiles and the table that follows, while sharing some properties, each kit is unique either in approach or in the features offered.
Capitalizing on the ragged ends created by some thermophilic polymerases, in particular the 3´A overhang left by Taq polymerase, the first generation of PCR-based cloning kits used vectors with compatible overhangs. These so-called TA vectors, still among the offerings by CLONTECH, Invitrogen, Genpak, and Promega, employ vectors with T overhangs to complement PCR fragments with A overhangs.
As other thermophilic enzymes with specific and different extendase activities--that is, they leave different ends (see The End Table)--came into use, other approaches needed to be devised. Blunting the ends of PCR fragments ...
