Step I: The DNA of a bacterial cell is located in the cytoplasm (1), but also in the plasmid, an independent, circular loop of DNA. The gene to be transferred (4) is located on the plasmid of cell 1 (...Step I: The DNA of a bacterial cell is located in the cytoplasm (1), but also in the plasmid, an independent, circular loop of DNA. The gene to be transferred (4) is located on the plasmid of cell 1 (3), but not on the plasmid of bacterial cell 2 (2). Hence one can easily obtain either double‑ or single‑stranded forms of thes plasmids. {The "blue" comes from the blue‑white screening for recombinants that can be done when the multiple cloning sites are in the b‑galactosidase gene.
Step I: The DNA of a bacterial cell is located in the cytoplasm (1), but also in the plasmid, an independent, circular loop of DNA. The gene to be transferred (4) is located on the plasmid of cell 1 (...Step I: The DNA of a bacterial cell is located in the cytoplasm (1), but also in the plasmid, an independent, circular loop of DNA. The gene to be transferred (4) is located on the plasmid of cell 1 (3), but not on the plasmid of bacterial cell 2 (2). Hence one can easily obtain either double‑ or single‑stranded forms of thes plasmids. {The "blue" comes from the blue‑white screening for recombinants that can be done when the multiple cloning sites are in the b‑galactosidase gene.