Phagemid vectors are commonly used for “phage display technology” by which a broad range of proteins and peptides can be expressed as fusions to phage coat proteins and displayed on the viral surface. The advantage of phagemid vectors is that double stranded phagemid vectors can be converted into single stranded vectors and packaged into virion particles by infecting the cells with helper phage.

•  Phagemid has certain advantages over phage vectors:

►  The carrying capacity of phagemid is higher than phage vectors.

►  Phagemid has higher efficiency in transformation than phage vectors.

►   Phagemids are genetically more stable than recombinant phage vectors.

► Phagemids can be exploited to generate single stranded DNA template for sequencing purposes.

►   Single stranded phagemid vectors inside the phage can be targeted for site-directed mutagenesis.

►   Single stranded vectors can be used to generate hybridization probes for mRNA or cDNA.

Fig1-4.5: Phagemid vector for phage display

[Source : Huan Qi, Haiqin Lu, Hua-Ji Qiu, Valery Petrenko and Aihua Liu (2012); Phagemid Vectors for Phage Display: Properties, Characteristics and Construction; J.Mol. Bio (417), 129-143]