Explain recombinant DNA formation and bacterial transformation

Foreign DNA is cut and joined into a plasmid vector, then inserted into E. coli by transformation.

The diagram shows how foreign DNA is inserted into vector DNA/plasmid and then transferred into E. coli cells.

• Foreign DNA – DNA fragment to be inserted
• Vector DNA / plasmid – circular DNA used to carry the foreign gene
• Restriction enzyme – cuts both foreign DNA and plasmid at specific sites
• DNA ligase – joins foreign DNA with plasmid DNA
• Recombinant plasmid – plasmid containing foreign DNA
• Transformation – entry of recombinant plasmid into bacterial cell
• E. coli – host bacterium used to multiply recombinant DNA
• Cells divide – bacteria reproduce and make copies of recombinant DNA