Bacterial Transformation: What? Why? How? and When?

Transformation is one of the few options for horizontal gene transfer. Though transformation is a natural process, yet only a handful of the organisms are able to perform it naturally. The process of bacterial transformation is also a step of pivotal importance in the field of genetic engineering. The rDNA which is an exogenous DNA, is required to be inserted and expressed in the suitable host. However, majority of the hosts are unable to take up exogenous DNA. Thus, it requires some artificial methods too. The induction of the ability to take up such DNA is called competence. Several methods are being tried since the inception of its concept, but none of them are found to be universal. Therefore, there is a constant requirement of newer methods having advantage and efficiency over the existing ones. The conventional method involves CaCl2 treatment followed by heat shock for achieving transformation. There is also employment of device oriented high end methods like electroporation or ultrasound mediated transformation etc. The efficiency of such methods varied widely and is often specific to a host. Thus, this review is focused on the necessity of transformation and various options that are available to researchers for performing bacterial transformation. It also attempts to strike a comparative study of the existing techniques.