2.12. Pull‐down assay with biotinylated H19

To identify whether H19 could pull down miR‐22‐3p, the cardiomyocytes were also transfected with biotin‐labelled Bio‐probe NC, Bio‐LncRNA H19‐WT and Bio‐LncRNA H19‐Mut. 48 hours later, the cells were lysed and incubation with M‐280 streptavidin magnetic beads as described above. Afterwards, the beads were washed with pre‐cooled lysis buffer, low‐salt buffer and high‐salt buffer in sequence. Subsequently, the RNA complexes bound to the beads were purified by TRIzol, the level of miR‐22‐3p was tested by RT‐PCR.