Fig. 5. The 185/333 proteins are on the surface of small phagocytes. Confocal images of 185/333⁺ coelomocytes that were labeled for 185/333 proteins prior to fixation show spherical structures present at the edge of the cell (A, arrows) and on filopodia (B, arrow; C, arrows) that appear as knobs on the membrane. The cell in A has a spread morphology in contrast with those in B and C with a more highly filopodial morphology. The 185/333 proteins are not present in the perinuclear region, and anti-actin labeling was negative (not shown), both of which are consistent with a lack of membrane permeabilization. This result suggests that some of the 185/333 epitopes are present on the extracellular face of the plasma membrane. Bars, 10 µm.