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Selectable genetic markers are exogenous genes that are introduced into a cell, conferring a previously absent selective advantage. These markers are primarily used to "mark" the successful ligation of DNA into a plasmid and subsequent transformation into a cell. Oftentimes, selectable markers are accompanied by other exogenous genes that is the primary gene of interest; the marker simply serves to distinguish between successful transformations, and unaltered wild-type cells. | Selectable genetic markers are exogenous genes that are introduced into a cell, conferring a previously absent selective advantage. These markers are primarily used to "mark" the successful ligation of DNA into a plasmid and subsequent transformation into a cell. Oftentimes, selectable markers are accompanied by other exogenous genes that is the primary gene of interest; the marker simply serves to distinguish between successful transformations, and unaltered wild-type cells. | ||
It is not atypical to witness transformation efficiencies as low as .05%, making it difficult to pick correct cellular colonies without additional techniques. This is where the selectable genetic markers prove their usefulness. For instance, selectable genetic markers can be used to confer ampicillin resistance to E. coli. These newly resistant E. coli can then be grown on culture plates with ampicillin, allowing only E.coli with successfully transformed DNA to proliferate. | It is not atypical to witness transformation efficiencies as low as 0.05%, making it difficult to pick correct cellular colonies without additional techniques. This is where the selectable genetic markers prove their usefulness. For instance, selectable genetic markers can be used to confer ampicillin resistance to E. coli. These newly resistant E. coli can then be grown on culture plates with ampicillin, allowing only E.coli with successfully transformed DNA to proliferate. | ||
In addition to selectable genetic markers are screenable genetic markers. Screenable genetic markers function in a similar manner in that they are exogenous genes that are transformed into a cell; however, they do not confer any new sort of resistance to the cell. Instead, they cause the cell to respond differently to environmental conditions in such a way as to distinguish transformed cells from untransformed cells. This can be useful when determining the transformation efficiency of a cell, or when carefully monitoring the activity of proteins. | In addition to selectable genetic markers are screenable genetic markers. Screenable genetic markers function in a similar manner in that they are exogenous genes that are transformed into a cell; however, they do not confer any new sort of resistance to the cell. Instead, they cause the cell to respond differently to environmental conditions in such a way as to distinguish transformed cells from untransformed cells. This can be useful when determining the transformation efficiency of a cell, or when carefully monitoring the activity of proteins. | ||
==Types of Selectable Markers== | ==Types of Selectable Markers== | ||
