Question

The AmpR gene on plasmid pGLO gives cell resistance to Ampicillin. Explain what that means and how this gene provides that.

Answer 1

pGLO is a plasmid vector used in recombinant DNA technology to transfer a gene into the desired organism during the creation of a genetically modified organism. An ideal vector should have one or two marker genes and in the pGLO, the Green florescent Protein gene and Ampicillin resistance gene are the markers. GFP gene codes for a Green protein and isolated from a jellyfish Aequorea victoria. The ampicillin resistance gene codes for a protein called beta-lactamase which can break the beta-lactam ring present in the ampicillin antibiotic. The marker genes are used to screen the success of gene cloning and vector transformation. For example, the ampicillin gene is commonly used to screen the success of the transformation. After ligating the gene of interest into the pGLO it will have to transfer into the host cells for expression. This transfer can be achieved through various methods like chemical mediated transformation, Electroporation, or any other methods. Since none of these methods are 100% efficient, the cells should be screened for the presence of vectors after transformation. For that the will plate into the media containing antibiotic ampicillin since the cell without plasmid did not have the antibiotic resistance mechanism, they cannot live on the media. But the cells with plasmid can live on the antibiotic-containing media due to the production of beta-lactamase enzyme. This is how screening is done using the ampicillin resistance gene.