Bacille pyocyanique observé en microscopie optique à fluorescence
Co-marking DNA breaks in HeLa cells produced by a laser, observed using fluorescence microscopy. The breaks are shown in yellow, as a result of co-marking with the red colour of the breaks mixed with the green of the protein XRRC1, which bonds to them. Here, scientists are analysing the distribution of the DNA breaks across various types of cells, in order to determine which repair pathways are active, and identify any possible interactions between them. Cancer cells have a high proportion of breaks in their DNA. Therapeutic agents used in cancer treatment inhibit the repair pathways for such breaks.