Chapter 15 The breasts/Fig 15.23.jpg

You can download this figure by right-clicking it and choosing 'Save Picture As...'

Fluorescent in-situ hybridization (FISH) for the HER2 gene. The number of copies of the HER2 gene in the tumour cell nucleus is assessed with fluorescence microscopy and the number of signals (red dots) is counted per cell and compared with the number of signals for chromosome 17 (green dots). A ratio of HER2 gene to chromosome 17 of more than 2 is considered positive, as here.