Figure 1.

Gating strategy to identify sputum granulocytes. (a) A forward-/side-scatter (FSC/SSC) gate is used to exclude most debris and lymphocytes. (b) Subsequently, cells positive for CD11b and negative for ∼450 nm autofluorescence were gated to exclude residual lymphocytes and alveolar macrophages (which are highly autofluorescent). (c) The resulting granulocytes were subdivided into neutrophils and eosinophils based on SSC and expression of CD16. (d) The resulting neutrophil and eosinophil population show FSC/SSC patterns similar to those in blood, with a higher SSC for eosinophils and higher FSC for neutrophils.