Transformation

• What is transformation? In cloning, PCR products which already were ligated into pGEM®-T Easy Vectors are cloned using E.coli (JM109) competent cell, prior to sequencing. Since transformation usually produces a mixture of relatively few transformed cells and an abundance of non-transformed cells, a method is necessary to select for the cells that have acquired the plasmid. The transformed cells with plasmid, however, need not contain the desired recombinant DNA inserted in cloning experiment. Various techniques may be further employed to screen for transformed cells that contain plasmid with an insert. Reporter genes can be used as markers, such as the lacZ gene which codes for B-galactosidase used in blue-white screening.