Introduction

Transformation is the process by which a bacterium takes up and expresses exogenous DNA, resulting in a newly acquired genetic trait that is stable and heritable. For transformation to occur, bacterial cells must be in a particular physiological state, referred to as competency, in which bacterial cell walls is made permeable to macromolecules such as DNA. E.coli can artificially be made competent when treated with chloride salts of the metal cations calcium, magnesium, and rubidium. In addition, abrupt transitioning between heat and cold can induce competency. It is believed that metal ions and temperature changes affect the structure an permeability of the cell wall and membrane, allowing DNA molecules to pass through. Transformed cells will grow on selective medium that contains antibiotic. To ferry foreign genes into bacteria, plasmids are usually used. Plasmids are self replicating extra chromosomal, double stranded circular DNA molecules found in many strains of bacteria. Only bacteria cells that take up the plasmid will survive selection on ampicillin agar plates and will produce green fluorescent colonies which will be visible under the long wave U.V. Light. The transformation efficiency rate for E.coli with a green fluorescent protein plasmid would be higher under the condition "LB/Amp+" due to the facts that plasmids are used to ferry foreign genes into bacteria and transformed cells will grow on selective medium that contains an antibodies.