In recent years, advances in imaging probes, microscopy techniques and bioinformatics image analysis have markedly expanded the imaging toolbox available to developmental biologists. Apart from conventional phenotypic studies, embryonic development is increasingly investigated in vivo with improved accuracy in time and space and more detailed quantitative analyses down to the single-cell level (reviewed in 1). To get more insight into the elaborate chemical and mechanical dynamics that underlie development, my laboratory addresses the growing imaging needs of the biological community by developing assays2, imaging technologies3-5, and reagents6,7 for carrying out imaging with i) high spatiotemporal resolution at the single-cell level and with ii) sensitivities down to individual proteins. Such newly introduced and future imaging tools can then be used as a means of performing qualitative and quantitative imaging in order to mechanistically dissect development, disease progression, and tissue regeneration in vivo.