The gene, once cloned into the cloning vector ( called entry clone in this method ), may be conveniently introduced into a variety of expression vectors by recombination.
22.
Once cut, scientist can then insert the desired DNA fragment possessing " sticky ends " into a circular DNA molecule, and ligate them together to create an engineered cloning vector.
23.
Some plasmids contain an M13 bacteriophage origin of replication and may be used to generate single-stranded DNA . These are called phagemid, and examples are the pBluescript series of cloning vectors.
24.
The number of clones that constitute a genomic library depends on ( 1 ) the size of the genome in question and ( 2 ) the insert size tolerated by the particular cloning vector system.
25.
Restriction mapping is a very useful technique when used for determining the orientation of an insert in a cloning vector, by mapping the position of an off-center restriction site in the insert.
26.
For example, pBR322 is a low copy number plasmid ( ~ 20 copies / cell ) from which several very high copy number cloning vectors ( ~ 1000 copies / cell ) have been derived.
27.
TetA is also present in the widely used E . coli cloning vector pBR322 ( where the sequence that confers resistance, containing only the TetA gene, is also often referred to as Tet R ).
28.
Cloning is generally first performed using " Escherichia coli ", and cloning vectors in " E . coli " include plasmids, bacteriophages ( such as phage ? ), cosmids, and bacterial artificial chromosomes ( BACs ).
29.
For example, if a DNA sample is going to be used in a cloning experiment, the step that follows its running on an agarose gel is to ligate ( covalently link ) to a cloning vector ( most likely a plasmid ).
30.
Example of cloning vectors used for this test are pUC19, pBluescript, pGem-T Vectors, and it also requires the use of specific " E . coli " host strains such as DH5? which carries the mutant " lacZ?M15 " gene.
