The DH10B-derived cloning background is suited to high-complexity plasmid libraries, genomic or cDNA libraries and large constructs. The high-efficiency chemically competent preparation is specified at no less than 1 × 10¹⁰ CFU per µg of control DNA. The cells are prepared for chemical transformation, allowing direct use with the appropriate transformation protocol. It is supplied as 6x50µl, stored at -80°C, and has a stated shelf life of ≥ 15 months.