What are the advantages and disadvantages of using a selection gene?

In vitro: a selection gene allows selection of only cells expressing your gene of interest, creating a fairly homogenous population. This is useful for determining transduction efficiency and expression. In addition, increasing the stringency of selection (by increasing the amount of selection antibiotic in the media) biases toward a population of high expressing cells.

In vivo: selection genes are immunogenic; leading to an immune response that rejects the cells or virus expressing the selection gene. Thus we recommend using selection genes only in immunocompromised mice (nude, SCID, etc).

In general, we recommend using selection genes for in vitro work, but avoiding them for in vivo applications.