Fluorescent confocal image of SY5Y cells stained with phospho- LIN28- S134 antibody. SY5Y cells were fixed with 4% PFA (20 min), permeabilized with Triton X-100 (0.2%, 30 min). Cells were then incubated with AP3732a phospho- LIN28- S134 primary antibody (1:100, 2 h at room temperature). For secondary antibody, Alexa Fluor® 488 conjugated donkey anti-rabbit antibody (green) was used (1:1000, 1h). Nuclei were counterstained with Hoechst 33342 (blue) (10 μg/ml, 5 min). Note the highly specific localization of the phospho- LIN28 immunosignal mainly to the nucleus, supported by Human Protein Atlas Data .