Takara Bio's bacteriophage packaging pUC118 and pUC119 Vectors contain an intergenic region (IG region) of the M13 phage DNA, enabling their replication in the form of single-stranded DNA once transformed into bacteria with the helper phage M13K07. Single stranded pUC118 and pUC119 Vectors can then be packaged into phage particles and released from bacterial cells. Using this system, there is almost no single-stranded helper phage contamination. Furthermore, single-stranded DNA fragments of up to 7 kb can be stably obtained with no inherent deletions. pUC118 and pUC119 Vectors contain the same multiple cloning sites as pUC18 and pUC19, respectively.