MODEL RELEASED. Biological research. Researcher examining cells under a microscope. The cells are displayed on two computer monitors next to the researcher. The red rings on the screens show the presence of protein in muscle fibres. Antibodies have been used to attach fluorescent dyes to specific cell tissues (immunofluorescence), making it easier for the researcher to identify different parts of the cells. Photographed at the Genethon Laboratory, near Paris, France.