High efficiency gene transfer into mammalian cells.

We have generalized the protocol of gene transfer, greatly increasing the variety of cells that can be used as recipients of foreign genes. Our approach has been to use a transient assay system that allows rapid screening of expression of foreign DNA. When the initial steps of gene transfer have been optimized with the transient system, these defined conditions are used to yield efficient stable transformation. We have seen that primate cells, including human cells, can be used in gene transfer experiments at levels sensitive enough to allow detection of single copy gene function. Recently we have also used this approach successfully with undifferentiated embryonic cells.