For immunofluorescence analysis, Osteoprogenitors differentiated from Bone marrow Mesenchymal stem cells were fixed and permeabilized for detection of endogenous RUNX2 using Anti-RUNX2 Recombinant Rabbit Polyclonal Antibody (Product # 711519, 5 µg/mL) and labeled with Goat anti-Rabbit IgG (Heavy Chain) Superclonal™ Secondary Antibody, Alexa Fluor® 488 conjugate (Product # A27034, 1:2000). Panel a) shows representative cells that were stained for detection and localization of RUNX2 protein (green), Panel b) is stained for nuclei (blue) using SlowFade® Gold Antifade Mountant with DAPI (Product # S36938). Panel c) represents cytoskeletal F-actin staining using Rhodamine Phalloidin (Product # R415, 1:300). Panel d) is a composite image of Panels a, b and c clearly demonstrating nuclear localization of RUNX2. The images were captured at 60X magnification.