Recombinant DNA Technology Lecture Notes

Recombinant DNA Technology & PCR

Introduction to Recombinant DNA Technology

• Definition: Recombinant DNA technology involves combining DNA from different sources to create new genetic combinations. This often utilizes bacterial plasmids as vectors.

• Key Components:

  • Vector DNA: Typically a plasmid, a small, circular DNA molecule found in bacteria, separate from the bacterial chromosome. Plasmids are crucial for carrying the gene of interest into a host cell.

  • Gene of Interest (Target DNA): The specific DNA sequence from another organism (e.g., human) that is to be cloned or expressed.

  • Restriction Enzymes: Molecular scissors that recognize and cut DNA at specific nucleotide sequences (restriction sites). They create sticky ends or blunt ends, which are essential for inserting the gene of interest into the vector. An example is EcoRI, which recognizes the sequence G A A T T C.

  • DNA Ligase: An enzyme that forms phosphodiester bonds to join DNA fragments (e.g., the gene of interest and the linearized plasmid vector) together, sealing the recombinant DNA molecule.

  • Host Cell: A cell (often a bacterium like E. coli) that takes up the recombinant DNA and replicates it. The host cell provides the environment for the expression or cloning of the gene.