Figure 3.

Circulating tumor cells (CTCs) detected on ISET filters after filtration of diagnostic leukapheresis product of non-small-cell lung cancer (NSCLC) patients. CTCs were detected with immunocytochemistry in three different manners: Cells positive for the epithelial cell adhesion molecule (stained red) with CD45 (stained brown) as a negative marker (A); TTF1 or p40 (stained brown) as a positive marker, with CD45 as a negative marker (stained red); (B) and a combination of TTF1 with EpCAM (C). Images were taken with a focus of 200×. White arrow: 8 µm pores of the filter. Red arrow: two cells suspected to be EpCAM and TTF1 positive; black arrow: TTF1-positive, EpCAM-negative cell, blue arrow: EpCAM-positive cell.