A phage display vector with improved stability, applicability and ease of manipulation.

We modified a combinatorial library display vector, pCOMB3, to provide a stable, easily manipulated, high-copy vector for the display of a random hexapeptide library. The propensity of the original phagemid to accumulate 800-1000-bp deletions in the region of the cloning site has been eliminated. Furthermore, the small 63-bp 'stuffer' at the cloning site was replaced with a 2114-bp DNA fragment from adenovirus 2. This produced a 5808-bp vector, that we have named pICD1LS, with the appropriate characteristics for single-peptide phage display. Libraries of greater than 10(6) molecules were produced with this vector.