METHODS AND APPARATUS FOR BINDING ASSAYS

摘要

The present teachings relate to methods, systems, and apparatus for low cost label-free assay detection. The present teachings, in a variety of embodiments, employ opposing forces to detect signals which depend on the number of charges on and/or the size of a particle. The particle, which can be subjected to opposing forces, can have specific capture probes at its surface. As analytes of interest are captured by the particle, the number of charges on the particle surface and/or the size of the particle is changed. A particle parameter or kinematic property such as the position, velocity, acceleration or force of/on the particle can be measured, and results obtained relating, for example, to the present, absence, quantity, and such, of one or more analytes of interest. Various embodiments are described for efficient, high throughput assays of samples potentially including one or more analytes of interest, such as bioanalytes. As well, various embodiments are described wherein binding assays can be carried out without the need or use of extrinsic labels. A number of embodiments provide, for example, methods, systems, and apparatus for detecting analytes (such as nucleic acids, proteins, cells and other entities, particulates, and the like) in one or more samples. Also described are: detection of a single copy of a target biomolecule, such as DNA, captured onto a trapped (e.g., tethered) bead; protocols for fabricating encoded bead arrays for multiplex assays; and methods, systems and apparatus for efficient and specific capture of pathogen biomolecular markers onto bead-bound capture probes, as well as detection and measurement of such capture events.