Calu-1 and KG1A cells were incubated with 0.2 U/mL of Vibrio cholerae sialidase for 60 minutes at 37°C. Cells were then washed and stained with each CD164 MoAb indicated or with an isotype-matched negative control MoAb and counterstained with PE- or FITC-conjugated isotype-matched anti-Ig. The median fluorescence for each cell group was determined by analysis on a FACSCalibur, and the percent binding determined as indicated in Materials and Methods. Values are means ± SD of three determinations.