Cloning

Successful cloning and subsequent protein expression requires highly efficient DNA transformation. The process of altering a cell so that it acquires and expresses genetic material from a surrounding environment is transformation. This process is commonly used to introduce recombinant plasmid DNA into bacterial strains which can be made competent by artificial means. Chemically competent cells are calcium chloride-treated to facilitate attachment of the plasmid DNA to the competent cell membrane. Cells are subsequently heat-shocked which opens the pores in the cell membrane so plasmid DNA from the surrounding environment can enter the cell. Electrocompetent cells are prepared for transformation using electroporation for a few milliseconds. This method uses an electrical pulse to create pores in the membrane so that the material can enter the cell from the surrounding environment.