Figure 1

Schematic representation of tibia sectioning for RNA collection. Tibiae were serially sectioned using a precision bone saw to obtain bone slices representing discrete areas. Three successive bone slices were prepared according to calibration measurements previously determined from toluidine blue stained sections of aged-matched rodents. The section of primary interest was obtained from the initial slice and included the entire articular cartilage layer and proximal subchondral bone (~760 μm) and measured a total of 960 μm. Slice 2 was predominantly epiphyseal bone and growth plate and measured 1440 μm. The third slice included the adjacent 1440 μm containing metaphyseal bone. Sections two and three were collected as internal controls.