A) Zeta potential of suspended BMDMs coated or not with high molecular weight HA, followed by HAase treatment where noted. Bars represent means ± SEM. n=3. B) BMDM left untreated or treated with intact or denatured α2–3,6,8 neuraminidase for 30 min. Cells stained with Cy5-conjugated Sambucus nigra agglutinin (SNA) or Alexa 488-conjugated peanut agglutinin (PNA), lectins that recognize terminal sialic acid or galactose, respectively. Scale bar, 10 μm. C) Cells treated as in B, but lifted into suspension and measured for zeta potential as in A. D) Zeta potential determinations for indicated IgG-opsonized particles. Bars represent means ± SEM. n=3. E) BMDM, treated as in B and challenged with phagocytic targets. Normalized binding index of IgG-opsonized beads is from >5 fields of >10 cells each, n=3. Bars represent means ± SEM. See also Figure S2 for additional zeta potential measurements, Siglec expression, and the functional effect of SHP1/2.