Localization of cyclin B1 mutants in COS-1 cells by indirect immunofluorescence. Hoechst dye 33342 immunofluorescence (Left); α-lamin immunofluorescence (Center); and mAb P5D4 immunofluorescence (Right) to detect cyclin B1 derivatives: cyclin B1Ala (A), cyclin B1Glu (B), NLS–B1Ala (C), NLSmut–B1Ala (D), CRSAla–B1Ala (E), and CRSGlu-B1Glu (F).