Bob Sinclair | Aug 20, 2000 | 8 min read
Early attempts to design vehicles for the cloning of foreign DNA produced vectors that were too big, unstable, or unselectable. The tide turned in 1977 with the construction of pBR313, the direct ancestor of the well-known pBR322, which forms the basis of many vectors that are still used extensively today.1 However, the cloning systems introduced in the last year or so seem to be about as related to pBR313 as Ferraris are to little red Radio Flyer wagons. Some of the new protein expression syst