Cell phenotype identification

To identify the phenotype of isolated cells from primary lung cancer and adjacent tumor-free tissues, flow cytometry was used to detect the surface markers on these cells. When growing to the confluence of 70%, cells were enzymed and rinsed with ice-cold PBS twice. Cells were suspended at the density of 10⁷/mL with staining buffer and aliquoted to 100 μL. Fluorescein-conjugated mouse anti-human CD73, CD90, CD105, CD166, CD14, CD19, CD34, CD45, and HLA-DR antibodies (BD, USA) were added to the aliquots and incubated on ice for 30 min. After incubation, cells were washed twice, suspended with staining buffer and detected by flow cytometry immediately.