Quantum-Si said it is laying off about 20% of its workforce and pushing the Proteus protein sequencing system launch to Q2 2027. The proteomics company previously targeted early-access availability this summer and a full commercial launch by year-end. Quantum-Si attributed the delay to an “integrated instrument design cycle,” citing manufacturing repeatability and consistency risks across integrated Proteus units, with performance variation seen in internally produced instruments. The company also said reagent development remains largely on track for launch with reagents capable of detecting 19 or 20 amino acids. The revised timetable is expected to extend cash runway from Q2 2028 to Q4 2028, reflecting a common survival strategy among instrument developers when production yields and performance consistency become the gating factor for scale-up.