Detection of Transgene Integrants and Homologous Recombinants in Mice by Polymerase Chain Reaction

The use of genetically altered mice in research has increased exponentially since the production of the first transgenic mouse 15 yr ago. Within the past decade, the technique of targeted mutagenesis in mice has seen a similar rapid expansion in use, becoming a strategy widespread throughout a number of laboratories studying a variety of experimental systems. In addition to the large number of new transgenic and knockout models being generated, many investigators are now performing combinatorial experiments in which various transgenic and/or knockout mice are intercrossed to produce animals with complex genotypes. These rapid experimental advances have necessitated the development of tools that permit efficient and precise identification of genetically altered alleles in mice. Many investigators use Southern blotting to identify transgenic founder mice or mice bearing homologous disruptions; however, this strategy often becomes laborious when large breeding programs are involved. PCR is a technique that lends itself very well to rapid identification of large numbers of mutant mice bearing complex genotypes. These large-scale analyses are often required when performing experiments with transgenic and knockout animals.