AN EXPRESSION VECTOR ENCODING A LACZ REPORTER GENE FACILITATES IDENTIFICATION OF STABLE, HIGH-PRODUCING CHO CELL CLONES

We describe a vector and a streamlined procedure for isolating high-pr oducing stable mammalian cell transfectants. The vector encodes the Es cherichia coli lacZ gene as a reporter. We show that levels of beta-ga lactosidase activity, assayed in situ in clonal isolates, can be used to identify clones producing high levels of the protein of interest (i n this case, soluble human CD4 protein). (C) 1997 Academic Press.