What are Phasmids: Lamda phage att sites and plasmids

The regions on the phage and bacterial genomes in which the recombination occurs are termed attachment sites
Phage functional att site length is around 240-base pairs and its core sequence length is 15bp (GCTTTTTTATACTAA) respectively
The genetic combination of plasmid vector and attachment (att) sites of ʎ phage DNA are termed phasmids
These Vectors contain regulatory elements of both plasmids and ʎ phages for replication and propagation in suitable hosts
These phasmids may insert into the ʎ genome by means of site specific recombination using att sites
This is a reversible recombinational insertion of plasmid into phage is referred to as lifting the plasmid and generates a phage genome containing one or more plasmid molecules
Phasmids can be used as plasmid while cloning of DNA fragments and the recombinants can be stored as phage particle because they have infinite shelf-life
Screening of phage particles gives much cleaner results than the bacterial colonies
It can be used as phage cloning vector from which recombinant plasmid can be released