Figure 1
Analysis of membrane-bound HER2 level on SKBR3 cells. (A) Membrane-bound HER2 on SKBR3 cells were labeled with an Affibody-quantum dot (QD) to visualize the locations of HER2. Light microscopic image from the QD fluorescence channel acquired for a control group of SKBR3 cells without drug incubation. The typical HER2 distribution, as found in the bulk cancer cells, is characterized by higher HER2 densities (appearing in orange and yellow) on membrane ruffles and at the cell periphery than in flat regions. Three rare flat/resting cells lacking membrane ruffles are marked with asterisks. The QD fluorescence signal is shown in false color (red hot LUT) to better discern the HER2 distribution patterns. (B) Overlay of the original red fluorescence channel image, with the corresponding direct interference contrast (DIC) channel image, yielding additional information of the membrane topography. These overlay images were used to manually mark all individual cells, except incompletely imaged cells at the image borders and small spherical cells. The marking resulted in distinctly coloured regions of interest each defining the area used for the measurement of total membrane-bound HER2 per cell, as calculated from the intensity in the QD-channel image. Scale bars: 100 μm.
