Figure 5. TUNEL labeling of anterior cruciate ligament transection (ACLT) induced osteoarthritic right knee of 8-months old female C57BL/6J mice. (A) The anterior cruciate ligament of knee-joint was removed through surgical knife and OA was established after 1 month. The HA, PRP, and HA+PRP were injected into right knee after establishment of ACLT-OA for one month. After sacrifice, the right knees biopsies were collected for TUNEL assay to detect cellular apoptosis. (B) Histologic hemotoxylin and eosin (H&E)-stained sections revealing ultrastructural architecture of articular cartilage in knee joint of control, OA, HA, PRP and HA+PRP group. The upper panel (a-e, respectively) represent lower magnification (500µm). The dotted rectangular areas in lower magnification images are shown as higher magnification (200 µm) (f-j, respectively). (C) Representative images of TUNEL staining in the knee joint after cartilage green staining indicating TUNEL positive (apoptotic) cells against a DAPI (blue) nuclear counter stain.