Recombinant DNA

Learn what rDNA is and what it does

Basics

What is rDNA (recombinant DNA)?

DNA that has been formed artificially by combining constituents from different organisms.


What is a plasmid and how does it relate to rDNA?

a genetic structure in a cell that can replicate independently of the chromosomes, typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan. Plasmids are much used in the laboratory manipulation of genes.


How rDNA is made:

DNA is extracted from the cell of a donor organism or biological source. It must then be purified from other cellular molecules such at RNAs, proteins, and structures such as cell membranes. One common method for DNA extraction is by ultracentrifugation of cell components in a density gradient made up with ethidium bromide in cesium chloride. So in simpler terms, the needed gene is cut from a DNA molecule.


To do this scientist use a restricting enzyme the gets the exact required gene needed. This restricting enzyme cuts up very specific DNA sequences. The process ensures that inaccurate, incorrect or unwanted sequences are generated and become accidentally incorporated into the final recombinant DNA. This could and most likely would result in cell death.


A bacterial plasmid is cut using the same restricting enzyme used for the DNA. By doing this it ensures the required gene and the plasmid are complementary to the ends of the needed gene. For the required gene and the plasmid to be connected the enzyme DNA ligase is needed in a process called ligation. The result is a recombinant plasmid that returns to the bacteria cell. As the bacteria reproduces the required gene is cloned.


Application of rDNA technologies and why it matters:

You can find rDNA in every western pharmacy, doctor's or veterinarian's office, medical testing laboratory, and biological research laboratory. This is important because it's very accessible to just about anyone.


  • It gives people the sense that rDNA isn't such a big deal.
  • People can stop showing regard for human life as much.
  • They think a life doesn't matter because they can be remade.
  • People will be playing God
  • People will have to much power.


Personal opinions about the use of rDNA:


I think it's a great tool that can help people but knowing human nature it will be used for wrong reasons so I don't think we shouldn't use it.


Transgenic animals:

A transgenic animal is an animal that has a foreign gene deliberately placed in their genome. The first transgenic animals available to the American public was a mouse. They were able to change the gene of a mice and offspring had the same genes.