Aortic VCAM-1 expression in A2^−/− and A2^+/+ mice treated with IgG-APS. A2^−/− or A2^+/+ mice were treated with either IgG-APS, IgG-NHS, LPS, or PBS, as described in “Determination of endothelial VCAM-1 expression in en face preparations of mouse aoura using quautum dot bioconjugates and α-photon excitation laser-scanning microscopy.” VCAM-1 expression was determined by immunostaining using a specific quantum dot bioconjugate, and quantified after examination using a dual photon laser confocal microscope. Fluorescence intensity in AU (mean ± SD; n = 10 images/mouse and 2 mice/group). ¶Statistically different from A2^+/+ treated with PBS (P = .001). ¶¶Statistically different from A2^−/− treated with PBS (P = .017). *Statistically different from A2^+/+ mice treated with IgG-NHS (A; P = .001) or MuMoAbC (B; P = .001). **Statistically different from A2^+/+ mice treated with IgG-APS (A; P = .001) or 4C5 (B; P = .017).