It has been used for mineral staining in osteoblast cultures. However, positive staining with TRAP helps make the diagnosis. Skeletal development in zebrafish using alcian blue-Alizarin. The actual blue color comes from a Prussian blue reaction. Carpenter AE, Jones TR, Lamprecht MR, Clarke C, Kang IH, Friman O, et al. Oxford University Press is a department of the University of Oxford.