A rapid and versatile method for the detection and isolation of mammalian cell lines secreting recombinant proteins.

The secreted-protein agarose diffusion immunoassay (SADI) described here is an efficient and time-saving method for identifying cell lines secreting recombinant protein products. In addition to significantly reducing the labor involved in identifying clones of interest, it also increases the possibility of detecting rare transformants by allowing the screening of a large number of clones simultaneously. The recovery of viable cell lines following the technique is nearly 100%. We demonstrate that the assay can be used to differentiate between clones producing two different protein products and that it is possible to use the technique to identify and isolate the high-producing recombinant clones in a population. Given an available antiserum, it should be possible to adapt this assay for any secreted protein of interest.