From Macro to Micro: The Importance of Bacterial Transformation and Discoveries of Gel Electrophores

Written by: Aminah Rangwala

Transformation of bacteria can date earliest back to the 1900s and has evolved ever since, where scientists have been making discoveries about our genetic material, DNA, that they didn’t know existed. Bacteria is essential for the growth of the human growth cycle and can be classified into the branch of Prokaryotic. They are needed for the decomposition of organic matter and have later been seen to transform.

Image Credit: Muhammad Dawood Khan

Bacterial transformation can be classified as the process of transferring a foreign genetic material into a cell. Bacteria contain their DNA as plasmids or small circular disks that carry a gene of interest. Therefore, one of the main purposes for bacterial transformation is to introduce a plasmid into a bacteria and replicate the plasmid in the cell to see further results that you are testing for. Another use of bacterial transformation includes duplicating DNA, called DNA cloning. In other words, a gene of interest is derived from a testing source and inserted into a plasmid. This new plasmid is referred to as a recombinant plasmid or recombinant DNA. To see if a transformation is successful, the DNA will be incorporated into one of the cell’s chromosomes.

In the midst of bacterial transformation, there is also a process called gel electrophoresis. Gel electrophoresis is a process that is used for separating nucleic acids or other macromolecules based on their size, shape or physical properties. Bacteria can be closer analyzed with this method and this technology allows us to study the sequence, expression, and function of a gene.

Image Credit: Muhammad Dawood Khan

As shown in the picture to the right, samples of DNA such as ones from bacterial transformation are placed into wells or indentations in the gel on one side. Each well can be labeled based on the bacteria and each side of the gel is either positive or negative. The smaller bands of DNA move quicker whereas the larger bands of DNA move slower. This is identified as the different sized molecules form bands in the gel. Because DNA is negatively charged, gravitationally, the DNA will attract to the positive side of the gel.