Supplemental File 2: List of antibodies used in this study. Name Origin -tubulin DM1A, Santa Cruz ACTBD11B7, Santa Cruz custom 3-19, Abcam -actin CENP-A CENP-A CENP-A CENP-B CENP-C HJURP HJURP TBP H50, Santa Cruz ab25734 ,Abcam Ab33034, Abcam Bethyl H277, Santa Cruz Ab63766, Abcam H5, Covance Activated RNA Polymerase II (RNAPIIS2P) RNA CTD4H8, Polymerase Santa Cruz II ChF: chromatin fiber Immunoprecipitation Dilution for Western Blot Dilution for immunofluorescence 1:100 1:100 1:1000 1:40000 (cell), 1:200 (ChF) 3 g 1:1000 3 g 1:1000 5 g 1:2000 1:1000 1:100 1:400 (cell), 1:50 (ChF) 1:400 1:2000 1:400 (cell), 1:50 (ChF) 1:500 1:500 1:50 1:1000