Abstract
LINE1 is the most active and abundant family of retrotransposons; it is implicated in a number of pathologies, as well as in early embryo development. We present a protocol to specifically knockdown LINE1 in mouse embryonic stem cells and embryos, including details for the nucleofection and zygote microinjection of LINE antisense oligos, followed by RNA FISH validation. This protocol can be used in development, as well as other cell types where LINE1 is believed to be expressed. For complete information on the use and execution of this protocol, please refer to Percharde et al. (2018).