Quantum-Si disclosed it is laying off about 20% of its workforce and delaying the Proteus protein sequencing system launch to the second quarter of 2027. The proteomics company said the change is tied to adding an “integrated instrument design cycle” before moving to production, citing repeatability and consistency risks across internally produced integrated units. Alongside the personnel reductions, Quantum-Si estimated cost actions generating roughly $12 million in annualized operating expenses, extending its cash runway from Q2 2028 to Q4 2028. The company also updated Proteus reagent plans for amino-acid coverage at launch. The Proteus timing shift highlights the gap between prototype performance and scalable manufacturing readiness for next-generation proteomics platforms.