Fig. 3.
Immunostaining for plasma-membrane-localized HER2. Cells were fixed with paraformaldehyde (pH 7.4) in the absence of detergents. Trastuzumab IgG was used as the primary antibody, with a human-Fab-specific, FITC-conjugated secondary antibody. a Representative transmitted-light and fluorescence images of Hc7 and MCF7 cells after immunofluorescence staining. b Quantitation of average FITC fluorescence per cell for three cell lines: Hc7, which overexpresses HER2; MCF7, which expresses physiological levels of HER2 and, as negative control, CV1, which has no HER2 expression (dotted line indicates the fluorescence of the CV1 negative control; error bars represent SEM; ANOVA: F2,36 = 75.97)