Novel Fixed Z-Dimension (FiZD) Kidney Primordia and an Organoid Culture System for Time-lapse Confocal Imaging

Tissue, organ and organoid cultures provide suitable models for developmental studies, but our understanding of how the organs are assembled at the single cell level still remains unclear. We describe here a novel Fixed Z-Dimension (FiZD) culture setup that permits high-resolution confocal imaging of organoids and embryonic tissues. In a FiZD culture a permeable membrane compresses the tissues onto a glass coverslip and the spacers adjust the thickness, enabling the tissue to grow for up to 12 days. Thus the kidney rudiment and the organoids can adjust to the limited Z-dimensional space and yet advance the process of kidney morphogenesis, enabling long-term time-lapse and high-resolution confocal imaging. Since the data quality achieved was sufficient for computer-assisted cell segmentation and analysis, the method can be used for studying morphogenesis ex vivo at the level of the single constituent cells of a complex mammalian organogenesis model system.