Figure 3.

Recombinant BMP-2 did not induce the formation of cartilage and bone in cultured tongue. Staining images with Alizarin red (A, B, C) and Alcian blue (D, E, F) in the middle portion of E13 tongues cultured for 8 days in BGJb medium containing the vehicle (A, D) and 4 μg/ml of recombinant BMP-2 (B, E). Staining images of longitudinal section of hind limb containing tibia and fibula of E17 embryo and Meckel's cartilage of E11 embryo are shown as a positive control of Alizarin red and Alcian blue in C and F, respectively. B, D, and E used the same magnification as A.