DNA constructs are purified and microinjected into pronuclei of mouse zygotes, with 150-200 zygotes routinely injected per construct. Efficient microinjections are performed using our innovative electro-impulse microinjection technology, which ensures high embryo survival, minimal cellular damage, and reliable DNA delivery. The injected DNA integrates into mouse genome and can be transmitted through the germ line. Our unit also performs pronuclear injections of BAC DNA constructs. Identification of the transgenic mice is carried out using real time qPCR and the positive mice are further analysed by Southern blot analysis of their tail biopsy DNA. Microinjections are repeated at no additional cost if no positive transgenic animals are obtained in the first round (or initial rounds). 

Researchers may either provide their own DNA constructs for injection, or TRAM can generate constructs on their request. In conventional transgenic models, insertions are typically random and multicopy. At TRAM, we have developed specific methodological modifications to optimize transgene integration, including strategies to promote single-copy insertion when requested.