Fig. 6

TRAP staining of cells following osteoclast differentiation in conjunction with methyl green nuclear counterstaining. A–H Hematopoietic cells from an PBMC-derived iPSC line A–D or a fibroblast-derived iPSC line (E–H) that had been differentiated either according to an embryoid body-based (EB) (A, B, E, F) or a monolayer-based (MB) protocol (C, D, G, H) were seeded onto calcium-phosphate coated wells and further subjected to osteoclast differentiation conditions. Representative images of cells derived from EB protocols show large TRAP positive cells (A, B, E, F) with multiple nuclei (solid arrows in B, F). Resorption pits are also visible in both groups (white dashed lines in A, E). Cells derived from the MB protocol did not give rise to osteoclasts. Cells with a stellar-like cell morphology can be seen in the fibroblast-derived iPSC MB differentiation group (empty arrows in H). Scale bars: A, C, E, G = 250 µm, B, D, F, H = 50 µm