Sequence notation
Lambda DNA
Restriction enzymes


All Lambda clones made in the Simple Cloning Lab have plasmids with a similar structure (see below, circle on the right) :

Between the unique EcoR I and BamH I sites in pGT4 (see above, circle on the left) a BamHI-EcoRI fragment from Lambda DNA (shown in red) is inserted using the enzyme ligase ("ligated"). Since recombination of (parts of) the vector (pGT4) and donor (Lambda DNA) has occurred, the plasmids are called recombinant plasmids (pGTλ plasmids).
The Lambda fragment present in the recombinant plasmid is called insert.
Depending of which fragment from Lambda DNA is inserted, the size of the plasmid varies.

In the Simple Cloning Lab, the name of the pGTλ clone shows the size of the insert.
For example, the pGTλ3758 plasmid, is the 3758 bp EcoRI-BamHI fragment from Lambda DNA inserted in pGT4.

Since the BamH I site is in the tetracyclin resistance gene, insertion of a Lambda DNA fragment between the BamH I and EcoR I sites of the vector results in disruption of the gene. This can be used to select for recombinants.