Microscale Characterization of Undecalcified Bone Tissue Using Correlative Atomic Force Microscopy and Histology

Characterizing bone tissue in its mineralized state remains technically challenging. Conventional approaches typically compromise mechanical integrity through decalcification or lack the structural resolution necessary to capture microscale heterogeneity. Here we present an integrated workflow combining atomic force microscopy (AFM) with histological and immunofluorescence assays on adjacent undecalcified bone tissue cryosections. Using a tape-transfer mounting approach, we resolve mechanically and structurally distinct tissue types within a minimally processed single mouse femur section. Furthermore, we show that decalcification substantially alters nanoscale surface topography and local mechanical properties. Applied to an aging cohort of C57BL/6J female mice spanning 7 to 115 weeks, the proposed method detects age-associated changes in bone matrix structure and stiffness. The approach provides a practical methodology for spatially correlating nanomechanical properties with molecular markers in bone and other mineralized tissues, with broad applicability to disease models including cancer metastasis, osteoporosis, and osteoarthritis.