Overview of 4D DIC microscope images of C. elegans embryo. (A) Schematic of 4D DIC microscope images. Digital images of a developing embryo were recorded in multiple focal planes and a set of multifocal images was recorded with a fixed time interval, α. (B) Example of 4D DIC microscope images of a C. elegans embryo. Each column shows multifocal images recorded at a specific time point, with 3.5 μm between two focal planes. Each row shows time-lapse images recorded in a specific focal plane with 160 s between two time points. Bar is 10 μm.