De Novo Generation of Murine and Human MADR Recipient Cell Lines for Locus-Specific, Stable Integration of Transgenic Elements

Mosaic analysis by dual recombinase-mediated cassette exchange (MADR) is a technology that allows stable and locus-specific integration of transgenic elements into recipient cells carrying loxP and FRT sites. Nevertheless, most cell lines lack these recombination-specific sites. This protocol describes a method to introduce the minimum requirements into cells, leading to the generation of de novo primary MADR recipient cells or MADR "Proxy" cells. These cell lines allow the combinatorial use of a wide range of transgenic elements through MADR. For complete details on the use and execution of this protocol, please refer to Kim et al. (2019).