Nearly all biological systems – from development, to regenerative medicine, to cancer – are spatially organized and multicellular. Until recently, we did not have the tools to explore diverse cell types and their interactions within the native tissue spatial context. Single cell biology, in which Caltech's faculty have been pioneers, is poised to transform how we study the life sciences. This field replaces low resolution data on heterogeneous populations of cells and tissue, with precise, spatially and temporally resolved information at the cell-type specific level. New technical capabilities at Caltech in optofluidic cell culture allow for functional characterization and recovery of single cells, and for exquisite pairing of phenotypic information to genotypic state for thousands of individual cells in each experiment. These advances enable unprecedented insights into complex biological processes and rare cells.