ECOS™ 101 (DH5α) Competent Cells. Features - Suitable for cloning with large plasmid and cDNA library construction, and also allow blue-white colony screening. Applications - Cloning and subcloning, scale up application OR blue-white screening. Efficiency > 3 x 10^8 - Recommended for high efficiency cloning, cloning low abundance transcript, general cloning, gene library.