Biotechnology

What is Biotechnology? The manipulation of genes in order to affect the resulting traits of organisms It has revolutionized how scientists study various fields Genetics Biochemistry Forensics

Recombinant DNA In recombinant DNA, DNA from two different sources, often two species, are combined into the same DNA molecule. DNA cloning permits production of multiple copies of a specific gene or other DNA segment. To work directly with specific genes or to make large amounts of gene products, scientists prepare gene-sized pieces of DNA in identical copies, a process called gene cloning.

Restriction Enzymes In order to make recombinant DNA, we need restriction enzymes Bacterial restriction enzymes cut DNA molecules at DNA sequences called restriction sites. A restriction enzyme usually makes many cuts, yielding restriction fragments. The most useful restriction enzymes cut DNA in a staggered way, producing fragments with “sticky ends” that can bond with other DNA fragments. DNA ligase seals the bonds between restriction fragments.

Polymerase Chain Reaction (PCR) Used to produce many copies of a specific target segment of DNA. A three-step cycle—heating, cooling, and replication— brings about a chain reaction that produces an exponentially growing population of identical DNA molecules.

Cloning

Gel Electrophoresis Indirect method of rapidly analyzing and comparing genomes. Uses a gel as a molecular filter to separate nucleic acids or proteins by size by exposing them to an electrical field. The phosphate groups in the sugar-phosphate backbone of DNA are negatively-charged.

In gel electrophoresis, the molecules move through the gel at different rates, determined largely by their size and charge. Shorter molecules move through the gel faster than longer molecules.

DNA Fingerprinting An individual’s unique collection of DNA restriction fragments, detected by electrophoresis and nucleic acid probes.