sentence: For quantitative detection of sites of 2 ’ - O ribose methylation , RiboMethSeq was performed on total RNA extracted from HCT116 cells mock-transfected ( No siRNA ) or transfected for 3 days with one of two siRNAs targeting mRNAs encoding TFIP11 , DHX15 or coilin or with an irrelevant siRNA ( siCtr ) .