Immunological detection of gene expression in recombinant clones

After ligation and transformation, a number of clones will (it is hoped) be obtained that can be identified as recombinants by the occurrence of insertional inactivation, by analysis of small-scale plasmid preparations, or more specifically by in situ hybridization. An additional strategy that is superficially attractive, but not without considerable problems, is to look directly for expression of the cloned gene(s). This may be applicable in primary cloning if no specific DNA probe is available, but is more generally used in subsequent studies of expression of specific foreign genes.