Analysis of PML bodies purified from cultured cells. (A) Fluorescence microscopy comparing U2OS PML^−/− cells (lower) with the U2OS PML^−/− + YFP-PML cells (upper). Images captured using chicken anti-PML with Texas Red secondary (left panels) or YFP fluorescence (center panels). Right panels show the two channels merged with DAPI. Scale bars are 10 μm. (B) U2OS WT and U2OS PML^−/− + YFP-PML cells in quadruplicate were either untreated (−As) or treated with arsenic for 2 h (+As) and lysates analyzed by Western blotting with an antibody to PML. (C) Fluorescence microscopy of nuclear extracts from U2OS PML^−/− + YFP-PML cells either untreated (−As) or treated with arsenic for 2 h (+As). (D) Left panels show a widefield and right panels show four z sections through a single PML body (untreated). (E) Anti-PML Western blots of nuclear extracts either prior (Pr) to or post (Po) incubation with anti-GFP nanobody beads. (F) Anti-PML Western blot of material eluted from anti-GFP nanobody beads. Molecular weight markers are indicated in kD. Source data are available for this figure: SourceData FS1.