COWFISH2A+ as a versatile and accessible platform for digital bioanalysis

Digital bioanalysis enables single-molecule detection of biomolecules and holds transformative potential across the life sciences and clinical diagnostics. However, its broader translation remains limited by accessibility and versatility. Here, we present COWFISH2A+, a compact, fully automated device integrating wide-field imaging with a custom dispensing module. Using an open-type microchip, COWFISH2A+ enables diverse assays at low cost through direct liquid deposition. As a proof of concept, we demonstrate two types of digital bioanalysis: a digital enzyme assay and an amplification-free digital genetic assay, SATORI. The digital enzyme assay discriminates alkaline phosphatase, a blood biomarker, at the single-isozyme level with sub-femtomolar sensitivity, while SATORI achieves attomolar-level detection of multiple pathogen-derived genetic targets. Furthermore, to demonstrate the translational potential of SATORI, we directly test 159 clinical specimens, detecting SARS-CoV-2 from nasopharyngeal swabs within ∼20 min with 92% sensitivity and 85% specificity. COWFISH2A+ thus provides an accessible and versatile platform for digital bioanalysis.