Patent ID: 6284541
Filing Date: 2001-09-04
Classification: C07K,C12N

Abstract:
A method for introducing foreign DNA into a host cell by homologous recombination, comprising transfecting the host cell with a recombinant vector comprising:a) two flanking nucleotide sequences which are homologous to a target gene sequence in the genome of the host cell,b) a nucleotide sequence encoding a positive selection marker located between the two flanking nucleotide sequences,c) nucleotide sequence encoding a negative selection marker located outside the two flanking sequences, andd) each of b) and c) are operatively linked to an expression control sequence which is active in the host cell,wherein the negative selection marker comprises at least one nucleotide sequence encoding a polypeptide located on the cell surface, and wherein the negative selection marker is not expressed after a targeted integration of the vector into the genome of the cell by homologous recombination, and is expressed and presented on the cell surface after a random integration of the vector into the genome of the cell.