Phage screening advantage

Since its introduction, this technique has gained more and more importance in the combinatorial field. The main advantage of biological libraries, in comparison to chemical libraries, depends on the possibility of increasing remarkably the number of different molecules that can be screened at the same time. Furthermore, once the phage displaying the active sequence has been selected, it is able to replicate itself by infecting host bacterial cells successive selection and amplification cycles result in an exponential enrichment of the active peptide sequence. 

The lambda phage method is readily adapted to the screening of M13 plaques (Mason and Williams, 1985). However, best results are obtained when the lifts are directly baked, without lysis and denaturation steps (M13 is 55). It is also advantageous to use ds probes or to prepare probes complementary to the strand packaged in M13. 

Lambda vectors in general have two major advantages over plasmid vectors first, lambda DNA can be packaged Iji vitro for high transfection efficiencies (10 pfu/yg DNA), and secondly, phage plaque can be screened more efficiently than bacterial... 

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