Immunofluorescence was essentially performed as previously described (Warda et al. 2016 (link)). In brief, HeLa cells or HEK293 cells expressing YTHDC2-Flag were grown on coverslips and fixed using 4% paraformaldehyde in PBS for 10 min at RT. Cells were permeabilized using 0.1% triton-X-100 in PBS for 15 min before blocking with 10% FCS and 0.1% triton-100 in PBS for 1 h at room temperature. Cells were then incubated with an anti-YTHDC2 antibody (Sigma HPA037364) or an anti-Flag antibody (Sigma F3165) in 10% FCS and PBS for 2 h at room temperature, washed thoroughly and then incubated with a secondary antibody (Alexa Fluor 488-conjugated donkey anti-rabbit; Jackson ImmunoResearch) for a further 2 h. After further washing steps coverslips were mounted using medium containing DAPI (Vectashield; Vector Laboratories). Finally, cells were analyzed by confocal microscopy using a ConfoCor2 microscope (Carl Zeiss).