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 wi
th a single thymidine nucleotide at the 3' ends. Thus, these vectors w
ould be very useful for direct cloning of PCR-generated products with
high efficiency.