Broad Clinical Labs, in collaboration with Roche Sequencing Solutions and Boston Children’s Hospital, demonstrated an ultra‑rapid whole‑genome sequencing (WGS) workflow that produced variant calls from genomic DNA in roughly four hours on Roche’s Sequencing‑by‑Expansion (SBX) prototype platform. The team reported results on reference samples and prospective neonatal ICU cases and presented findings at ASHG and in a peer‑reviewed paper. The group sequenced 15 human genomes during early access testing and achieved a mean turnaround of about 4 hours and peak times under four hours. Investigators optimized extraction, library construction, Xpandomer synthesis, sequencing, and analysis to compress total time. The record sets expectations for same‑day clinical sequencing in acute settings, though broad clinical adoption will require validation of accuracy, workflow robustness, and commercial availability of SBX instruments.