Ttl triggered white led light source

Time-lapse imaging was conducted with a custom LabView program (National Instruments), which drove a TTL-triggered white LED light-source (ThorLabs) for illumination, as well as two automated stages (Newport), which traversed the x- and y-axes to capture multiple fields of view for each frame. Images were taken every 3 min (using 10×-magnification lens). We experienced one rare case of a longer gap between images; however, cell identities were preserved at all times and tracking ability was not affected. Lineage structure and time to division measurements were determined by manually tracking the recorded image series using ImageJ software (example image series shown in Supplemental Movie MS1). The trypsin release and reseeding and single-cell release image series were captured continuously using a lower magnification (4×) lens that captured the entire device image in a single field of view. These image series were analyzed with the assistance of custom Python code based on the OpenCV library package that pre-analyzed the movies and marked each cell with a different color to ease human analysis, which was performed with iMovie software (Apple, Inc.).

All devices were fabricated in 6-inch silicon-on-insulator wafers with 17-μm deep flow channels created with deep reactive ion etching and an anodically bonded Pyrex lid. Each six inch silicon wafer yields 100 devices. Fluidic connections were established by securing the devices to a Teflon manifold with PEEK tubing aligned to the access ports. This manifold was secured to a copper clamp maintained at 37 °C with a recirculating water bath (Thermo Scientific). Pressure-driven flow in the device was controlled with electronic pressure regulators (Proportion Air). All fluids were pressurized with 5% CO₂ (Airgas) to maintain long-term pH stability of the culture medium for cell growth. Time-lapse imaging was conducted with a custom LabView program (National Instruments) which drove a TTL-triggered white LED light-source (ThorLabs) for illumination as well as two automated stages (Newport), which traversed the x and y axes to capture multiple fields of view for each frame.