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Abstract
There is little known about the methods by which bacterial cells take up foreign DNA. There are however, a number of theories as to how this occurs. The first suggests that plasmid DNA, if condensed into small clusters, can pass through calcium channels present in a bacterial membrane. This theory is potentially flawed in that the calcium channels are too small to allow the passage of condensed DNA. A second theory suggests that plasmid DNA may not require any form of channel. Instead of simply being allowed to approach a bacterial membrane, the plasmid can allow loops of DNA to pass through the lipid bilayer into the cytoplasm of the cell, this initial action is followed by subsequent loops entering the cell until the entire length of the plasmid has passed through the membrane. Lastly, it has been suggested that an open-circular form of plasmid DNA may be able to use the calcium channels to enter a bacterial cell. In knowing that, the trivalent cations spermine and sperimidine, when used at specific concentrations, were capable of condensing plasmid DNA into spherical clusters, it was decided to test this action alongside the standard Hanahan protocol for transformation. Later, spermine and sperimidine were tested without the calcium chloride called for in the Hanahan protocol to assess the relative effects of spermine and sperimidine on the ability of bacterial cells to take up plasmid DNA without the presence of the competence inducing calcium ions. It was found that condensing DNA into spherical clusters was not conducive to increasing transformation efficiencies, therefore it can be suggested that plasmid DNA is not taken up better by bacterial cells when in a condensed form. The remaining theories regarding DNA uptake by bacterial cells remain to be investigated.