Development of Enzyme Digital Assays Derived from Single Molecule Detection

Abstract

Digital assays, which have evolved from single-molecule detection technology, are attracting attention as a new method of measuring individual cells, proteins, and nucleic acids. The digital assays are characterized by their ability to directly measure individual molecules, enabling us to perform absolute quantification without the need for calibration curves and to determine the heterogeneity of a population. We first developed a digital assay for enzymes and applied the principle to digital ELISA and digital influenza assays. We demonstrate that the digital assays for enzymes are not only a new enzymology tools, but also have a wide range of applications such as elucidating the nature of viral populations. We will discuss how these new analytical techniques are opening up uncharted territory.