Synthetic biology - A model organism: E. coli lyrics

If you already have an idea of how to look at the Parts registry and design your genetic devices using biobrick parts, you need to put these pieces of designed DNA into what is known as a biological cha**is, or a cell. Technically, you can modify any model organism (like fission yeast or E. coli). However, when you look at the standard parts in the Biobricks registry, most of them are optimized for E. coli. It readily accepts different parts and devices, making it very easy to use as a biological cha**is for your newly constructed biobricks. Before you can insert your designed device into the E. coli cha**is, you have to first create a competent cell. A competent cell is one that can take up foreign DNA. Competent cells can be made by inducing artificial competence in the laboratory. E. coli cells can be made artificially competent by either chemical induction or by electroporation. Both of these processes make holes in the cell wall and enable the DNA molecules in the solution to pa** through the wall into the cell. After making competent cells, DNA is incorporated into the cell by a process called transformation. Typically, you place your genetic device on a plasmid backbone, and transform the plasmid in E. coli. The plasmid needs an origin of replication which allows it to be replicated in the cell independently of the chromosome of the cell. Plasmid transformation can be used for selection and screening. This is accomplished by adding a selective marker to your plasmid, most commonly an antibiotic marker on the plasmid backbone and streaking the transformed E. coli on plates with the antibiotic present in the medium. An antibiotic marker is a DNA sequence on your plasmid with your gene of interest that codes for a protein that allows your bacteria to be resistant to a specific antibiotic. This way, only the E. coli cells that have your plasmid transformed in them will grow and the wild type will die due to the antibiotic present in the media. You can conduct further an*lyses on your cloned E. coli by extracting the plasmid DNA, doing polymerase chain reaction, or PCR and gel electrophoresis an*lysis on your cloned DNA. You can learn more about these basic protocols on websites like addgene, and also others referenced in the supplemental resources.