The P[acman] vector permits cloning of any size fragment of DNA (1 kb to 100 kb) for genomic rescue transformation. The vector is equipped with two origins of replication such that under the appropriate conditions the cloned plasmid can be replicated in high copy number (to amplify for molecular biology manipulations) or at low copy number (to stably maintain the large plasmid and ensure efficient and accurate recombineering). The multiple cloning site (MCS) is utilized to subclone the left and right homology arms (LA,RA), or left and right boundaries of the region of interest encompassing a gene from a large genomic clone, such as a P1 or BAC. Through recombineering-mediated gap repair this region is incorporated into the P[acman] vector. The presence of the 3' and 5' P element termini and eye color marker allow it to be transposed directly into flies using P transposase. However, attB-P[acman] contains an attB site that allows permanent integration at specific docking points (these are equipped with the complementary attP sequence) that have been created in the genome (see Docking Sites page) using ΦC31 transposase. Due to the size limitations posed by P transposase-mediated transformation, ΦC31-mediated transgenesis is preferred for large constructs.