3.3.4 Cloning DNA

The recombinant DNA molecule consisting of a vector carrying an inserted DNA segment is transferred to a host cell. Within this cell, the recombinant DNA molecule replicates, producing large number of identical copies known as clones. A number of cell types can be used as hosts for replication of cloned DNA;one of them is bacteria. Fig (7) shows the steps for the creation of recombinant DNA molecules and cloning it in bacteria using a plasmid vector.

However, to study gene expression and gene regulation of eukaryotic genes, it is more convenient to use eukaryotic hosts. The use of recombinant DNA has many applications in animal and medicine such as diagnosis of genetic diseases, construction of gene mapping. The most important is its use for gene transfer, which is very useful in gene therapy.