Highest cloning efficiency, > 5 x 109 transformants/µg
The XL1-Blue strains are an all-prupose line of competent cells that are ideal for routine cloning needs. The XL1-Blue strains were designed to provide a host for optimal propagation of both plasmid and lambda phage vectors. They allow for blue-white color screening, single-stranded rescue of phagemid DNA and preparation of high quality plasmid DNA. This strain is available in a wide variety of transformation efficiencies, including XL2-Blue which is a high-efficiency derivative, and in either chemically or electroporation-competent versions.