p66 is directed to the nucleus by a single nuclear localisation sequence and is located to sites of DNA repair following UV damage. U2OS cells were fixed and stained as described in Materials and Methods. Panels A and B: cells transiently transfected with the pEGFP-p66 construct were treated with 40 Jm-2 UV at 254 nm and fixed 30 minutes post-treatment. Panel A: EGFP-p66 detected by an anti-EGFP antibody (Roche) (green); panel B: PCNA detected by staining with the anti PCNA-antibody 3009 (red). Panels C and D: cells transiently transfected with the pEGFP-p66NLS construct. Panel C: EGFP-p66NLS detected with the anti-EGFP antibody (green); panel D: cells stained with the anti-PCNA antibody as described above.