Figure 3. The expression of COL13A1 and COL15A1 were reduced in DPC of mice HF. Skin biopsies of normal C57BL/6 mice were collected at the indicated age and processed for paraffin sections. COL13A1 (A) and COL15A1 (B) expression was visualized by immunofluorescence staining and counterstained with DAPI for nuclei. The DP was circled by white dashed lines in each HF. Scale bar, 50 μm.