FIGURE 3.

Palatal shelf cross-sectional surface measurement determining the number of CXCL12-positive immunostained cells/mm² within the mesenchyme. (A) The individual cross-sectional surface of the inner half (in green) and outer half (in orange) of each palatal shelf was measured. (B) A square scale bar was drawn in the microscopic picture of 1,000×1,000 μm (mm²) and the total number of pixels was determined (e.g., HO-2 KO E15: 1 mm² = 635,000 pixels), data not shown. The contour of the mesenchyme was drawn (yellow line). The number of pixels for this area was determines by the Fiji Image J 1.51n software (10,424 pixels). The number of CXCL12-positive stained cells within this mesenchymal area of the palatal shelves was counted (e.g., inner half contains 31 CXCL12-positive cells. The number of cells/mm² was calculated (635,000/10,424 × 31 = 1888 cells/mm²).