Kupffer cells in developing mouse liver. Fluorescence images showing Alexa 488 (green) F4/80 immunoreactivity and large 0.2 μm microspheres (red) labelling of cells in developing mouse liver. The left column (A, D, G J) presents F4/80 immunoreactivity. The middle column (B, E, H, K) presents microsphere fluorescence in the same sections as shown in A, D, and G. The right column (C, F, I, L) presents merged images from the left and middle columns. Top row, tissue from pup euthanized at P3; second row from P6, third row from P11, and bottom row from P14. Calibration bar in L = 50 μm for all images.