helper phage

The use of a helper phage can be eliminated by using 'bacterial packaging cell line' technology.

However, this led to the incorporation of more helper phage genomes rather than phagemid genomes.

The (+) and (-) orientations of the f1 intergenic region allow the rescue of sense or antisense ssDNA by a helper phage.

Phage P4 infects Escherichia coli and cannot engage in lytic growth without presence of a P2-related helper phage.

Filamentous helper phage and the DNA from lambda phage are utilised in phage display.

Helper phages are usually engineered to package less efficiently than the phagemid so that the resultant phage particles contain predominantly phagemid DNA.

The phagemid used to transform E. coli cells may be "rescued" from the selected cells by infecting them with VCS-M13 helper phage.

One particular SaPI, SaPI1, is encapsidated in and exits the host cell in particles assembled from proteins encoded by its helper phage.

The sequences include a polylinker sequence (MCS), antibiotic resistance sequence to ampicillin and an E. coli and f1 helper phage origin of replication.

Loss of phage infectivity can be avoided by using a phagemid plasmid and a helper phage so that the resultant phage contains both wild type and fusion pIII.

The hybrid expression phagemids can be electroporated into E. coli XL-1 Blue cells which after amplification and infection with VCS-M13 helper phage, will yield a stock of library phage.

Those that remain can be eluted, used to produce more phage (by bacterial infection with helper phage) and so produce a phage mixture that is enriched with relevant (i.e. binding) phage.

An advantage of using pIII rather than pVIII is that pIII allows for monovalent display when using a phagemid (Ff-phage derived plasmid) combined with a helper phage.

However, in 1970, Morton Mandel and Akiko Higa showed that E. coli may be induced to take up DNA from bacteriophage λ without the use of helper phage after treatment with calcium chloride solution.

Further rounds of panning are completed to ensure enrichment of the sample, by infecting bacterial cells with the eluted phage and helper phage and then collecting the [ZFP-displaying] phage produced for the next round of panning.