Nuclear Actin-Chromobody: NIH 3T3 cells (murine fibroblasts) transfected with the nuclear Actin-Chromobody (TagGFP2, green) and the Lamin-Chromobody (TagRFP, red) were starved in serum-free medium for 24 hours. Nuclear Actin-Chromobody probed endogenous F-actin assembly and distribution is shown 30 s after stimulation with serum. Courtesy of Matthias Plessner.