Fig. 3

Light microscopy images demonstrating the specificity of HER2 affibody-QD labelling on dissociated tumour cells. a Dissociated tumour cells with labelled HER2. b Negative control without Affibody incubation for dissociated cells from the same sample as shown in a. c DIC image from the boxed cell in a, acquired with a 63x oil immersion objective. d Dissociated breast cancer cells classified as HER2 negative. The cells were immobilized on a microchip with a silicon nitride window in a and c. In b, and d, the sample was placed in a glass bottom cell culture dish. The images represent an overlay of the fluorescence- and DIC signals except in c. The exposure settings of the fluorescence channel were the same for images a, b, d, and f. Scale bars 50 μm in a, b, d; 10 μm in c