New vectors for direct cloning of PCR products

We describe the construction of two new vectors for direct cloning of polymerase chain reaction (PCR) products. This was done by inserting a synthetic DNA fragment containing two adjacent XcmI sites between the Asp718 and BamHI sites of the M13mp18 and M13mp19 phages. Cleavage of these M13 derivatives with XcmI will result in a linearized vector with a single thymidine nucleotide at the 3' ends. Thus, these vectors would be very useful for direct cloning of PCR-generated products with high efficiency.