Neutrophil chemotaxis was assessed using the Neuro Probe ChemoTx W Disposable Chemotaxis system (Neuro Probe Inc. Gaithersburg, MD). The wells of the 96-well plate were filled with various concentrations of KC. A polycarbonate filter (8 μm pores) with a hydrophobic ring around the area over each well was placed on the 96-well plate and calcein-labelled neutrophils were added to each ring. The chemotaxis chamber, consisting of the polycarbonate filter and 96-well plate, was incubated for 30 min at 37°C in 5% CO 2 and then non-migrating neutrophils were removed from the upper side of the filter. The chemotaxis chamber was placed in a multi-well fluorescent plate reader (Synergy 4, BioTek, Winooski, VT) and the migrated cells were measured using the calcein fluorescence signal (excitation -485 nm, emission -530 nm). Neutrophil migration was expressed as a percent of the total number of neutrophils that were placed on the topside of the filter (% Total).