Phenotyping Intact Mouse Bones Using Bone CLARITY.

The bone is typically studied using traditional histology techniques, that is, serial sectioning and staining. While effective, these techniques are laborious and destructive, as the native 3D environment of the bone is not maintained. Presented here is a bone-clearing methodology, termed Bone CLARITY, which combines published techniques for clearing soft tissues, including delipidation for the removal of light-scattering membranes, hydrogel-embedding for the stabilization of fragile epitopes, heme elution for the reduction of blood-based autofluorescence; as well as specialized steps, including decalcification and progressive refractive index matching, for addressing the unique challenges posed by osseous tissue. This method renders the bone transparent and enables the detailed visualization of an intact tissue specimen at multiple spatial scales.