The pLSG-IBAwt1 vector is designed for high-level expression of target proteins without affinity tag in insect cells. The gene transfer into the polyhedrin gene locus of AcMNPV DNA is achieved by homologous recombination and the vector carries a polyhedrin promoter. The Co-transfection with BacPAK6 linearized AcMNPV DNA (Clontech) or with circular flashBAC modified AcMNPV DNA (Oxford Expression Technologies) allows the generation of recombinant baculovirus at very high efficiency through reconstitution of an essential gene (ORF 1629) and elimination of wild-type virus to great extent. For selection and propagation in E. coli, the vector carries an ampicillin resistance and the ColE1 origin of replication (pUC). Please note that cloning into pLSG-IBA Acceptor Vectors compulsorily requires the restriction enzyme Esp3I since no other MCS for the integration of a gene of interest is available. In addition to the direct cloning of the gene of interest into pLSG-IBA vectors with Esp3I, another option via a so-called Entry-Vector is possible.