This week, our Elementary Ed. Majors in Biology were experimenting with genetic engineering. This lab was super cool. They were learning how genetic engineering is a process that enables scientists to put a desired gene into a plasmid, or ring of bacterial DNA. The object of this lab was to use specific genetic engineering processes to transform bacteria with a gene that codes of Green Fluorescent Protein (GFP).
Bacteria naturally contain one or more small circular pieces of DNA called plasmids. The unique pGLO plasmid encodes the gene for GFP plus a gene for resistance to the antibiotic ampicillin called beta-lactamase. Ampicillin is an antibiotic that kills various bacterial strains. However, if a bacterium has a certain gene resistant to ampicillin then exposure to the drug ampicillin does not kill the bacterium.
The plasmid pGLO also incorporates a special gene regulation system, which can control expression of the fluorescent protein in transformed cells. The gene for GFP can be switched on in transformed cells by adding the sugar arabinose to the cells' nutrient medium. Selection of the cells that have been transformed with pGLO DNA is accomplished by growth on antibiotic plates. The transformed cells will appear white on plates not containing arabinose, and fluorescent green under UV light when arabinose is included in the nutrient agar medium.
The students seemed really engaged with this lab and were really excited to see their bacteria plates glow under UV light!
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| Glowing Bacteria! |
