pSLAB22

This vector allows cloning of large (up to 22 k.b.) DNA fragments in Escherichia coli cells.

This vector is a plasmid-bacteriophage hybrid (phasmid), 33,276 bp in length.

The phasmid contains:
1) the pUC119 plasmid portion that includes ColE1 replicon (ori) and Ap(R) genefor beta-lactamase (Ap(R)), which confers resistance to ampicillin;
2) the E. coli bacteriophage lambda genome portion that possess all phage genes required for propagation in the phage form (CDR) including signal required for initiation of DNA packaging into phage capsid (cosQ, N and B);

The map shows location of unique recognition sites for enzymes that can be used for insertion of sequences of interest into the phagemid.

The phasmid can be propagated as plasmid in host cells grown at 30^oC. The switch from 30^oC to 37^oC results in activation of phage genes responsible for development via phage litic pathway. Yet, the phasmid cannot be packaged since the size of the monomer genome is below and the size of the dimer is above the threshold limits of the capsid packaging capacity. Only phasmid derivatives carrying inserts between 6-22 k.b. in size can form viable phage particles both in vivo and in vitro.