λSCREEN™-1 is a novel multipurpose vector designed for cDNA library construction. As a bacteriophage lambda insertion vector, it has the advantages of high cloning efficiency, stability, and ease of screening by high-density plaque lifts. cDNA up to 8 kbp in size can be inserted directionally into EcoR I/Hind III arms using the OrientExpress™ cDNA cloning strategy. The cloning region is located downstream of T7 expression signals and vector-encoded peptides so fusion proteins containing the 260 aa T7•Tag^®, 6 aa His•Tag^®, and 15 aa S•Tag™ sequences can be produced in appropriate hosts. Libraries can thus be screened for expressed polypeptides with antibodies or other ligands, as well as with conventional nucleic acid probes. Plasmid subclones are produced by site-specific recombination at dual loxP sites in the vector; colonies containing pSCREEN-1 subclones are obtained simply by plating recombinants on an appropriate host in the presence of ampicillin (or carbenicillin). The plasmid moiety contains the same expression elements as pET vectors and is suitable for high-level expression of most target proteins without the need for further subcloning. The fusion tags enable the use of a variety of strategies for detection and purification of target proteins, and are removable with thrombin or enterokinase. An SP6 promoter proximal to the cloning sites also enables synthesis of non-fused RNA for probes and in vitro translation (e.g., with the Single Tube Protein^® System 3). The λSCREEN-1 EcoR I Arms Kit is also available for non-directional cloning into the EcoR I sites.. This product is covered under license from Brookhaven National Labs. Commercial entities need to obtain a research use license prior to purchase. Please contact your licensing department to confirm that your company already holds a research use license.