pUC118 and pUC119 are plasmid vectors developed for the preparation of single-stranded DNA. pUC118 and pUC119 were constructed by inserting the intergenic region (IG region) of the M13 phage DNA into the pUC18 and pUC19 plasmids, respectively. Infection by the M13K07 helper phage induces production of pUC118 and pUC119 as single-stranded DNA. Using this system, single-stranded DNA from large DNA fragments (up to 7 kb) can be stably obtained without deletion. Both pUC118 and pUC119 vectors contain multiple cloning sites (MCS).