Three-dimensional cellular visualization in mouse apical periodontitis using combined whole-mount staining and optical tissue clearing.

Apical periodontitis is an inflammatory disease involving lesions located within the jawbone. Histological evaluations generally require decalcification and sectioning, which has limited our understanding of the three-dimensional (3D) organization and spatial distribution of different immune cell types in these lesions. A recently developed technique combining tissue clearing and whole-mount immunofluorescent labeling allows us to acquire such information from the deep tissue without sectioning. However, whole-mount immunofluorescent labeling in the jawbone requires further development. Here we provide a straightforward and efficient protocol to achieve 3D immunofluorescent imaging of murine periapical lesions.