Deactivated Cas9-Engineered Magnetic Micromotors toward a Point-of-Care Digital Viral RNA Assay.

Digital nucleic acid assays, known for their high sensitivity and specificity, typically rely on fluorescent readouts and expensive and complex nanowell manufacturing, which constrain their broader use in point-of-care (POC) application. Here, we introduce an alternative digital molecular diagnostics, termed dCRISTOR, by seamlessly integrating deactivated Cas9 (dCas9)-engineered micromotors, extraction-free loop-mediated isothermal amplification (LAMP), low-cost bright field microscopy, and deep learning-enabled image processing. The micromotor, composed of a polystyrene sphere attached to a magnetic bead, incorporates a dCas9 ribonucleoprotein complex.