A Lethal gene called LG and a vector comprising the same as tool for zero background-cloning vehicles. The lethal gene is cloned into the last restriction site in such a way that when any exogenous gene is inserted into the Multiple cloning sites (MCS) region upstream of the lethal gene, the expression of the lethal gene is inhibited, and only clones harboring the exogenous gene survives while non-recombinants which express the lethal gene product dies. This ensures more than 95% cloning efficiency using this novel LG containing vector. The present vector exhibits additional advantages over the existing commercially available vectors. The LG containing vector could also be used for lysis of the bacterial cells.
