A deconvolved wide-field fluorescence microscope image of a section through the neural tube of a chick embryo. The fluorescent DAPI probe (blue) has been used to show up DNA, and a red fluorescent probe with an antibody to phosphorylated H3 histone (phospho H3) shows where mitosis is taking place. A green fluorescent probe attached to BrdU (5-bromo-2-deoxyuridine), an analogue of thymidine, indicates where DNA synthesis is taking place.