Figure 2. CD271 stem cell marker expression in C918 uveal melanoma cultures. The upper row of pictures demonstrates the morphology of two-dimensional (2D; A and C) and three-dimensional (3D; E and G) cultures of C918 uveal melanoma with the formation of prominent VM in 3D cultures. Arrows in E and G point to VM. Asterisks in E and G point to cells growing in monolayer on the Matrigel surface. Arrowheads in E and G point to cells growing on the bottom of the culture dish. Panel H demonstrates detection of CD271 expression by VM-forming tumor cells by immunofluorescence in 3D cultures. No CD271 expression was detected in 2D cultures (D). CD271 expression was also not detected in control 2D and 3D cultures where no primary antibody was used (B and F). Magnification: 200×.