Characterization of expression of a chimeric antibody using a dihydrofolate reductase (DHFR) procedure

Abstract

We efficiently expressed a chimeric antibody using a DHFR gene linked to crippled SV40 promoter and isolated a stable cell line secreting the antibody up to 19 μg/10ⁿ cells/day, which is about 40-fold increase in antibody yield compared to the initial transformants. During the amplification stages, the mRNA levels and the antibody secrection decreased with increase in gene copy number. The genes were remarkably amplified at the first amplification stage and thus about 12-fold increase in the productivity was obtained. The cell population become homogeneous after the last round of selection.