Confocal image and LSC analysis of PML NBs. (A) PML nuclear bodies induced by IFN-α (2000 U/mL) were visualized by immunostaining using monoclonal anti-PML. Pictures are a projection of confocal Z sections. (B) IFN-α–treated (2000 U/mL) and untreated H929 and OPM2 cells were immunostained with mouse monoclonal anti-PML followed by incubation with Alexa 488–conjugated secondary antibody. LSC analysis was performed as described in “Materials and methods”; 3000 cells per sample were scanned. PML NBs are represented by scattergrams of 2 parameters of LSC measurement. Green fluorescence integral represents overall fluorescent intensity within the nucleus, and green maximal pixels represent maximal fluorescent signal (brightest cells).