Figure 1.

ER and HER2 status determination in control cells and DTCs.

Phase, CK, ER, and HER2 staining for an ER-positive control (cell line MCF-7), a HER2-positive control (cell line SK-Br-3), and DTCs with four different subtypes (ER negative/HER2 negative, ER positive/HER2 negative, ER negative/HER2 positive, ER positive/HER2 positive). Arrows highlight the ER and HER2 staining: ER with specific staining of the nucleus with a low background, a strong nuclear, and no cytoplasmic or peripheral staining (red); HER2 overexpression as completely positive moderate or strong membrane staining (blue). The triple fluorescence labeling of CK, ER, and HER2 was performed on 106 cells, and phase analysis was performed in parallel. Magnification 40 ×. Scale bar: 10 μm.